Instrument Calibration for Portable Survey Instruments - Entire Document (Very Large)
G-10 CFR 835/E1 - Rev. 1
NOVEMBER 1994
IMPLEMENTATION GUIDE
For Use With Title 10, Code of Federal Regulations, Part 835
OCCUPATIONAL RADIATION PROTECTION
INSTRUMENT CALIBRATION for PORTABLE SURVEY INSTRUMENTS
ASSISTANT SECRETARY for ENVIRONMENT, SAFETY and HEALTH
FINAL GUIDE - FOR UNLIMITED USE and DISTRIBUTION
U.S. Department of Energy
IMPLEMENTATION GUIDE
G-10 CFR-835/E1 - Rev. 1
INSTRUMENT CALIBRATION for PORTABLE SURVEY INSTRUMENTS
CONTENTS Page
I. PURPOSE AND APPLICABILITY. . . . . . . . . . . . . . . . 1
II. DEFINITIONS. . . . . . . . . . . . . . . . . . . . . . . 2
III. DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . 5
A. Instrument Selection. . . . . . . . . . . . . . . . . 6
B. Instrument Calibration. . . . . . . . . . . . . . . . 7
C. Functional Testing. . . . . . . . . . . . . . . . . . 7
D. Maintenance . . . . . . . . . . . . . . . . . . . . . 7
IV. IMPLEMENTATION GUIDANCE. . . . . . . . . . . . . . . . . 7
A. Instrument Selection. . . . . . . . . . . . . . . . . 9
1. Physical Inspection. . . . . . . . . . . . . . . . 9
2. General Operations . . . . . . . . . . . . . . . . 9
3. Source Tests . . . . . . . . . . . . . . . . . . . 9
4. Instrument Calibration . . . . . . . . . . . . . . 9
B. Instrument Calibration. . . . . . . . . . . . . . . . 9
1. Precalibration Inspection/Test . . . . . . . . . . 10
2. Calibration. . . . . . . . . . . . . . . . . . . . 10
C. Functional Tests. . . . . . . . . . . . . . . . . . . 11
D. Maintenance . . . . . . . . . . . . . . . . . . . . . 12
E. Accuracy/Quality Assurance. . . . . . . . . . . . . . 13
1. Calibration Standards. . . . . . . . . . . . . . . 13
2. Reference Radiation Field Requirements . . . . . . 14
3. Maintenance of Standards . . . . . . . . . . . . . 14
4. Assessments. . . . . . . . . . . . . . . . . . . . 14
F. Laboratory Documentation. . . . . . . . . . . . . . . 15
1. Laboratory Protocol. . . . . . . . . . . . . . . . 15
2. Laboratory Records . . . . . . . . . . . . . . . . 16
3. Instrument Calibration Records . . . . . . . . . . 17
4. Instrument Location. . . . . . . . . . . . . . . . 17
G. Laboratory, Equipment, and Staff. . . . . . . . . . . 18
1. Laboratory . . . . . . . . . . . . . . . . . . . . 18
2. Instrument Calibration Equipment . . . . . . . . . 19
3. Calibration Staff Qualifications . . . . . . . . . 19
4. Calibration Staff Training . . . . . . . . . . . . 20
V. REFERENCES . . . . . . . . . . . . . . . . . . . . . . . 20
VI. SUPPORTING DOCUMENTS . . . . . . . . . . . . . . . . . . 22
VII. APPENDICES
Appendix A
10 CFR 835, Implementation Guide, and DOE Radiological
Control Manual Cross-Reference . . . . . . . . . . . 23
Appendix B
Standard Test or Calibration Conditions. . . . . . . . 24
Appendix C
Reference Sources for Calibration. . . . . . . . . . . 25
Section I - Purpose and Applicability
I. PURPOSE AND APPLICABILITY
This Implementation Guide (IG) provides an acceptable methodology for
establishing and operating a program for calibrating portable
radiological survey instruments that will comply with U.S. Department of
Energy (DOE) requirements specified in Title 10 of the Code of Federal
Regulations (CFR), Part 835, "Occupational Radiation Protection" (DOE,
1993a); hereinafter referred to as 10 CFR 835. For completeness, this IG
also identifies applicable requirements and recommendations contained in
DOE Order 5480.11, as amended, "Radiation Protection for Occupational
Workers" (DOE, 1992), DOE's "Radiological Control Manual" (DOE, 1994;
hereinafter referred to as the RCM (with the associated numbers denoting
the article numbers)), and secondary documents (American National
Standards Institute (ANSI) Standards, etc.) invoked by the above
documents. Appendix A of this IG provides a cross-reference of the
applicable material in 10 CFR 835, this IG, and the RCM.
This IG amplifies the regulatory requirements of 10 CFR 835, which are
enforceable under the provisions of Sections 223(c) and 234A of the
Atomic Energy Act of 1954, as amended (AEC, 1954). The requirements and
recommendations of the other DOE documents are enforceable through
contractual or administrative means.
Except for requirements mandated by regulation, contract, or
administrative means, the provisions in this IG are DOE's views on
acceptable methods of program implementation and are not mandatory.
Conformance with this guide will, however, create an inference of
compliance with the related regulatory requirements. Alternate methods
that are demonstrated to provide an equivalent or better level of
protection are acceptable. Contractors are encouraged to go beyond the
minimum requirements and to pursue excellence in their programs.
The word "shall" is used in this IG to designate requirements from 10
CFR 835, DOE Orders, the RCM, and secondary documents invoked by them.
The requirements of 10 CFR 835 are mandatory except to the extent an
exemption has been granted pursuant to 10 CFR 820, "Procedural Rules for
DOE Nuclear Activities" (DOE, 1993b) and are identified by a bolded and
underlined "shall." Requirements taken from DOE Orders, the RCM, and
secondary documents are mandatory to the extent they are invoked by a
contract or through administrative means.
Those facilities not subject to the requirements of 10 CFR 835 should
substitute the corresponding DOE 5480.11 requirements.
This IG does not specifically provide require- ments for calibration of
installed instruments or low dose rate instruments (<0.1 mrad/h (1
micro-Gy/hr)); however, some of the included guidance may be applicable to
such instrumentation. This IG also does not provide information on
outside interactions (accreditation activities) to maintain measurement
quality.
This IG is applicable to all DOE activities involving occupational
exposure to ionizing radiation of DOE employees and/or
DOE-contractor/subcontractor employees.
Section II - Definitions
I. DEFINITIONS
acceptance testing: Evaluation or measurement of performance
characteristics to verify that certain stated specifications and
contractual requirements are met.
accuracy: The closeness of agreement between the result of a
measurement and the true value of the measurand.
adjust: To alter the response by means of a variable, built-in control,
such as a potentiometer.
as low as reasonably achievable (ALARA): The "approach" to radiation
protection to manage and control exposures (both individual and
collective) to the work force and to the general public to levels as low
as is reasonable, taking into account social, technical, economic,
practical, and public policy considerations. "ALARA is not a dose limit
but a process" which has the objective of attaining doses as far below
the applicable limits of 10 CFR 835 as is reasonably achievable.
bias: A deviation, always of the same magnitude and direction, of
measurement value from the "true value".
calibration: To adjust and/or determine either:
(1) The response or reading of an instrument relative to a
standard (e.g., primary, secondary, or tertiary) or to a
series of conventionally true values; or
(2) The strength of a radiation source relative to a standard
(e.g., primary, secondary, or tertiary) or conventionally true
value.
Also see "instrument calibration" or "source calibration."
calibration points: The distances from a source at which the reference
values for the field intensity (exposure rates) are known or evaluated
for fixed conditions of collimation, attenuation and scatter.
check source: A radioactive source, not necessarily calibrated, used to
confirm an acceptable level of instrument response to radiation exposure.
coefficient of variation (relative error): The standard deviation
expressed as a percentage of the mean (i.e., (standard
deviation/x)(100)).
consistency: Agreement of a measurement's result with the appropriate
standard to within a specified level.
consistency demonstration: Use of a comparative device to directly
obtain measurement results that are demonstrated to be sufficiently in
agreement with the appropriate standard.
control chart: A plot of the results of a quality control action to
record and demonstrate that control is being maintained within expected
statistical variation or to indicate when control is or will be lost
without intervention.
conventionally true value of a quantity: The commonly accepted, best
estimate of the true value of a quantity. The conventionally true value
and the associated uncertainty will normally be determined by comparison
with a national or transfer standard, using a reference instrument that
has been calibrated against a national, or transfer standard.
correction factor: The factor by which the reading of an instrument is
multiplied to obtain the conventionally true value of the quantity.
decade: A range of values for which the upper value is a power of ten
above the lower value.
demonstrated consistency: See "consistency demonstration".
detector: A device or component that produces a measurable response to
ionizing radiation.
energy dependence: A change in instrument response with respect to the
specific energy of the radiation being measured for a constant exposure
rate.
free-space geometry: A calibration geometry in which the radiation
emitted from a bare or collimated source in air reaches the instrument
under calibration with minimal scatter from nearby structures.
functional tests: Tests (often qualitative) to determine that an
instrument is operational and capable of performing its intended
function. Such tests include examination of voltage settings, zero
settings, response to radiation, etc.
geotropism: A change in the instrument's reading, as its orientation
changes, due to gravitational effects.
instrument (radiation detection): A complete system consisting of one
or more subassemblies (e.g., detector, readout, etc.) designed to
quantify, when exposed to radiation, one or more characteristics of
ionizing radiation or radioactive material.
instrument calibration: (1) Adjustment of the response of a given
instrument to agree with the response of a standard instrument when both
are used to measure the same quantity under the same conditions; or (2)
determination of the response of a given instrument when measuring a
physical standard under well-defined conditions.
laboratory, secondary: A laboratory that maintains and uses a secondary
standard as its reference standard.
laboratory, tertiary: A laboratory that maintains and uses a tertiary
standard as its reference standard.
overload response: The behavior of an instrument when exposed to
radiation intensities greater than the upper measurement limit.
portable survey instrument: An instrument intended to be operated while
being carried by an individual.
precision: The degree of agreement of repeated measurements of the same
parameter.
proficiency test: A test of laboratory performance by intercomparison
of results obtained from calibration of a common instrument or radiation
source by both the laboratory under evaluation and a reference
laboratory.
quality assurance program: A program for achieving and verifying
quality.
quality control: Quality assurance actions that achieve and sustain
attributes of the material, process, component, system, or facility in
accordance with predetermined requirements.
range: All values between the lower detection limit and the upper
measurement limit.
reading: The indicated value of the readout.
readout: The device that conveys visual information regarding the
measurement results to the user.
reference field: Radiation fields in which reference values for the
field intensity have been established.
reference point: The geometrical center of the sensitive volume of the
detector which is generally located by a mark (or marks) on the detector
housing or instrument case.
reference value: The value of a particular quantity (e.g., exposure
rate) that characterizes a laboratory's radiation field. It is the
value to which the reading of an instrument under calibration is
compared.
response: The instrument indication produced as a result of some
influence.
scale: A sub-range of the total range of measurement.
sensitivity: For a given value of the measured quantity, the ratio of
the variation of the observed variable to the corresponding variation of
the measured quantity.
shall: Within the context of this Guide the word "shall" is used to
designate requirements from 10 CFR 835, DOE Orders, the RCM, and
secondary documents invoked by them.
should and may: Within the context of this Guide, the words "should" and
"may" are used to represent optional program recommendations and allowable
alternatives, respectively. Deviations generally require no specific
approval or justification; however exceptions or deviations to "should"
provisions referenced directly from the RCM require specific justification
and approval in accordance with Article 113.3 of that manual (i.e., RCM
113.3).
standard (instrument or source):
-- primary (or national) standard: An instrument, source, or other
system or device maintained by the National Institute of Standards
and Technology (NIST) (formerly the U.S. National Bureau of
Standards).
-- secondary standard: An instrument, source, or other system or
device that has been compared directly with a national standard.
Generally reserved for use as a laboratory standard.
-- tertiary standard: An instrument, source, or other system or
device that has been compared directly with a secondary standard.
Generally reserved for use as a laboratory standard.
-- transfer standard: A physical measurement device, typically a
measurement instrument or a radiation source specifically designed
for transport, that has been compared directly or indirectly with a
national standard. This standard may be used as a laboratory
standard.
-- working standard: An instrument, source, or other system or device
calibrated by comparison with a standard other than a National
Standard.
test: A procedure whereby the instrument, component, or circuit is
evaluated against certain criteria for satisfactory operation.
traceability: The ability to show, through documentation, that a
particular instrument or radiation source has either been calibrated
using the national standard or has been calibrated using a transfer
standard in a chain or echelon of calibrations, ultimately leading to a
comparison with the national standard.
type test: A test of one or more production instruments, of the same
design, to verify the actual operational performance characteristics
against the expected or advertised performance specifications.
Section III - Discussion
III. DISCUSSION
10 CFR 835.401(c)(2&3) and 403(b) require, in part, that "appropriate"
instruments be used to control exposure to radiation. They also require
that these instruments be routinely calibrated, maintained, and tested
(10 CFR 835.401(c)(1&4)). American National Standards Institute (ANSI)
Standard N323, "Radiation Protection Instrumentation Test and
Calibrations" (ANSI, 1983) is referenced in DOE Order 5480.11 and is
cited as a mandatory environment, safety, and health standard in DOE
Order 5480.4, "Environmental Protection, Safety, and Health Protection
Standards" (DOE, 1984). The measurement ranges of the instruments can be
inferred from the control levels in 10 CFR 835 and the expected
workplace conditions; however, 10 CFR 835 does not address the accuracy
of calibrations or measurements. ANSI N323 requires an accuracy of +-2%
for sources used in calibrations and an accuracy of +-10% for the
calibrated instruments.
Radiation monitoring instrumentation is one of the principal tools for
protecting workers and the public from excess exposure to ionizing
radiation. Instruments are used to establish controls for worker or
public access to the radiation environment, while a personnel dosimeter
provides a legal record of a worker's dose. Except for certain
electronic dosimeters, conventional dosimeters provide only a
retrospective record of dose; they provide the integrated dose over a
period of time prior to readout. Survey instruments are important for
indicating exposure dose rates, controlling radiation exposures, and for
verifying the dose received by workers. Neither an emergency response
program, nor the ALARA program required by 10 CFR 835.101(c), can be
operated effectively without the appropriate quantity of properly
functioning instruments that are appropriate for measuring the
radiation(s) of interest and for operation in the facility's physical
environment. In addition to measuring dose or dose rate to control
direct personnel exposure, instruments are used: (1) to control the
spread of contamination (e.g., surface-contamination monitors); and (2)
to assess the adequacy of radiological controls (e.g., survey meters or
environmental monitors). Contamination monitoring is important in the
control of contact exposures, personnel contamination, and internal
exposures through inhalation or ingestion.
DOE facilities are expected to maintain the quality of measurements in
their daily operations by establishing procedures required to ensure the
proper operation and calibration of the equipment. Thus, instruments
"shall" be selected for the task, properly calibrated, properly
maintained, and routinely tested (10 CFR 835.401(c)).
A. Instrument Selection
Instruments "shall" be selected to measure the types and energies of
radiation and the range of radiation dose rates or surface contamination
activities present within the facility (10 CFR 835.401(c)(2)). The
instruments "shall" also be selected to perform adequately under the
environmental and physical conditions that prevail within the facility
(10 CFR 835.401(c)(3) and RCM 562.4). Initial instrument selection "shall"
be made using knowledge of facility radiation types, energies,
anticipated or known ranges, and results of available instrument
performance and testing data (vendor or independent) (10 CFR
835.401(c)(2)). The selection process includes Type Testing and
Acceptance Testing.
Type Testing
Implementation of a formal instrument qualification (type testing)
process in accordance with the relevant portions of ANSI N42.17A,
"Performance Specifications for Health Physics Instrumentation -
Portable Instruments for Use In Normal Environmental Conditions"
(ANSI, 1989a), and ANSI N42.17C, "Performance Specifications for
Health Physics Instrumentation - Portable Instruments for Use In
Extreme Environmental Conditions" (ANSI, 1989b), is encouraged. It
is recognized, however, that independent contractor qualification
efforts to meet these requirements may result in significant
duplication of effort and resources. To assist the development of
this process and to avoid such duplication, the Office of Health is
developing a program for the coordinated qualification and testing
of radiological instruments used within the DOE complex (RCM 561).
Acceptance Testing
Prior to use, new instruments should be tested against selected
specifications of ANSI N42.17A as well as other specifications as
set forth in the purchase agreement. Instruments which do not meet
the selected specifications should not be accepted or used by the
facility. Acceptance testing may be based on only a sample of the
instruments purchased for the more difficult-to-test specifications
(temperature, energy response, etc.) but should involve 100%
testing for basic specifications.
B. Instrument Calibration
The instrument shall be calibrated within acceptable limits against a
standard with a known relation to national standards (ANSI N323 & RCM
562.1). The calibration "shall" be performed at the required frequency to
maintain an acceptable accuracy for measurements and "shall" not exceed
one year (10 CFR 835.401(c)(1)). ANSI N323 and NIST Special Publication
812, "Criteria for the Operation of Federally-Owned Secondary Calibration
Laboratories (Ionizing Radiation)" (NIST, 1991), have set forth criteria
for proper calibration.
C. Functional testing
The instrument "shall" be routinely tested during its use (10 CFR
835.401(c)(4) and RCM 551.2), and periodically examined and tested to
ensure that it maintains the required performance. This may require
detailed ANSI N42.17 testing or simple functional tests performed during
routine calibrations (ANSI N323, Section 3). During use in the field,
instruments "shall" be tested frequently with a check source to ensure
that the readings remain within prescribed limits, as required by 10 CFR
835.401(c)(4) and ANSI N323 (Section 4.6). Functional tests will also
include battery checks and other field checks, as prescribed by the
manu- facturer or facility. Damaged or malfunctioning instruments
should be promptly returned for maintenance.
D. Maintenance
Maintenance of portable survey instruments "shall" be provided (10 CFR
835.401(c)(1)) and a program for both preventive and corrective
maintenance should be established and documented (RCM 563.1).
Instruments shall undergo calibration prior to use following any
maintenance or any adjustment that voids the previous calibration (RCM
563.3).
Section IV - Introduction
IV. IMPLEMENTATION GUIDANCE
This section describes the basic requirements for conducting an
instrument calibration program for the selection, calibration, routine
testing and maintenance of appropriate portable radiation protection
instrumentation in support of DOE operations. This IG provides
requirements for an instrument calibration program that addresses
selection (acceptance testing), calibration, functional testing,
maintenance, accuracy/quality assurance, laboratory documentation,
facilities, equipment and staff. This IG does not specifically address
type testing. Additional guidance on type testing will be provided upon
establishment of the DOE program noted in the section above on
"Instrument Selection."
The essential elements of an acceptable portable instrument calibration
program are shown below with reference to 10 CFR 835, the RCM and ANSI
N323:
-- An instrument calibration program that assures that calibration
"shall" be performed on each instrument at least annually (10 CFR
835.401 (c)(1) & ANSI N323 (4.7.1));
-- a method to determine when instruments have been returned
out-of-calibration and a method to notify users of
out-of-calibration instruments (RCM 562.8);
-- a source-check system that permits monitoring of instrument
performance in the field (RCM 551.5 & ANSI N323(4.6));
-- an instrument maintenance program that promptly identifies problems
and ensures the proper repair and recalibration of instruments (RCM
563 & ANSI N323(4.6));
-- a full range of NIST-traceable radiation calibration sources that
cover the types and intensities of radiation necessary for complete
calibrations for the radiation fields encountered at the facility
(RCM 562.1 & ANSI N323(4.3.2, 5.1));
-- a quality assurance and constancy check program for standard
instruments that permits the facility to maintain the calibration
of its reference fields (RCM 562.1 & ANSI N323(5.3));
-- an internal audit program "shall" be conducted no less frequently
than every 3 years (10 CFR 835.102 & RCM 134.1); and
-- a records program "shall" be established that documents results of
maintenance and calibration performed on instruments used for area
monitoring and contamination control (10 CFR 835.703(d)(1) and RCM
761), includes the maintenance of training records (10 CFR
835.704(a) and RCM 725), documents the type of instrument and
changes to the instrument (10 CFR 835.704(e) and RCM 751.2), and
documents the results of internal audits (10 CFR 835.704(c) and RCM
743).
Further, the following elements should be in place:
-- Detailed procedures covering the calibration of reference sources,
support instruments, and field instruments (RCM 562.2);
-- a record system that permits tracking of all calibration
information (both the mainten- ance information and functional
tests, and the reference fields and field instruments) (RCM 761 &
ANSI N323(4.5));
-- properly trained staff with an adequate technical background in
instrument calibration (RCM 652, 654, & 655); and
-- a dedicated facility that permits calibrations without outside
physical interference (RCM 564.1).
DOE facilities that do not calibrate or test their own portable
radiation protection instruments but use such instruments are
responsible for ensuring that all requirements of this IG are met (RCM
564.2).
Section IV, Subsection A - Instrument Selection
A. Instrument Selection
Instrument selection consists of type testing and acceptance testing.
As noted in the discussion (Section III); type testing will not be
covered in this document.
An acceptance test should consist of: (1) physical inspection; (2)
general operations tests; and (3) source tests, and should precede the
instrument calibration. The physical inspections and general operations
tests should be performed on each instrument. The source tests should
be performed on a random selection of 10% of the instrument batch or
four instruments, whichever is larger. If one instrument in a sample of
a large quantity fails the test, an additional 10% should be tested. An
additional failure would require testing of the entire batch. It should
be noted that temperature response of instruments can vary with
components and that large changes can be observed at temperature
extremes that may be in the recommended range for an acceptance test.
If operation in temperature extremes or humidity extremes is
anticipated, tests should be performed at the extreme conditions using
an appropriate temperature/humidity chamber.
1. Physical Inspection
This consists of an inspection of instruments for broken parts, loose or
missing screws, loose or misaligned knobs, calibration potentiometers
not aligned with access holes, circuit boards not secured, loose wires,
loose connectors, loose components, testing of moving parts and making
sure that batteries are fresh and properly installed.
2. General Operation
This consists of switching to check battery condition, verifying the set
of the mechanical zero on the meter, testing the meter zero
potentiometer, checking for switching transients, checking for zero
drift on the meter, and checking for light sensitivity, if applicable.
3. Source Tests
These consist of checking source response, geotropism, variability of
readings, stability, temperature response, humidity response, and photon
energy response.
4. Instrument Calibration
The initial instrument calibration is part of the acceptance test and
should include a comparison of instrument linearity and overload
response against specifications.
Section IV, Subsection B - Instrument Calibration
B. Instrument Calibration
A formal instrument calibration (ANSI N323 (4.7.1), 10 CFR
835.401(c)(1)) "shall" be performed on each instrument at least annually.
The calibration shall (ANSI N323(4)) include a precalibration
inspection/test normally followed by a documented calibration over the
entire range of the instrument. Calibration for ranges where the
instrument is not intended to be used need not be conducted, as long as
the specific limitations on instrument use are clearly marked on the
instrument. The frequency of calibration should be adjusted to the use
of the instrument and its durability. The National Conference of
Standards Laboratories (NCSL), "Recommended Practice RP-1, Establishment
and Adjustment of Calibration Intervals" (NCSL, 1989) indicates that more
frequent calibrations should be performed when greater than 15% of
instruments are returned out of calibration at the selected calibration
frequency (a minimum of annually). This should include all returned
instruments that fail a source check in the field. NCSL/RP-1 also
indicates that if, for those instruments for which the calibration
cycle had been more frequent than annual, fewer than 5% are out of
calibration, then the cycle may be lengthened but is not to exceed one
year.
1. Precalibration Inspection/Test
Upon receipt and prior to any adjustments, instruments shall (RCM 562.8)
be tested on each scale to determine the present state of instrument
calibration. This is often referred to as an "as found" calibration and
should cover the ranges for which the instrument is expected to be used.
If any of the readings are greater than +20% or less than -20% of the
true value, the Radiological Control Organization shall be notified (RCM
551.5 & 562.8). The users of the instrument and their supervisors
should also be notified.
Prior to formal calibration, the following inspections and tests should
be performed:
-- The instrument should be free of significant radioactive
contamination (ANSI N323(4.1)) and all smearable contamination
(RCM, Table 2-2);
-- inspect the instrument for physical damage;
-- determine and record the "as found" calibration;
-- refer the instrument to the repair shop, as appropriate;
-- adjust the instrument meter to zero (ANSI N323(4.1)), according to
manufacturer specifications;
-- check the batteries or the power supply (ANSI N323(4.1)), to verify
proper operational voltages (Batteries should be replaced as
required);
-- turn on the instrument and allow it to warm up (ANSI N323(4.1)),
according to manufacturer specifications;
-- test and set electronic adjustments (ANSI N323 (4.1)), according to
manufacturer specifications. (This may include the high voltage,
zero set, internal time base(s), etc.); and
-- observe the zero setting for abnormal response due to drift.
2. Calibration
The reproducibility (precision) of the readings from the instrument
shall (ANSI N323(4.2.1)) be tested by repeatedly (ò3 times) placing the
instrument in the same radiation field and observing the readings. The
readings obtained should normally not deviate from the mean value by
more than 10%. In lieu of routine testing of reproducibility, the
facility may have documented tests from a sample of instruments showing
that the reproducibility does not vary over several calibration periods.
Instrument calibration shall (RCM 562.1) follow the adjustment and test
requirements for linear, logarithmic, and digital readout instruments as
specified in ANSI N323. All calibration points shall (ANSI N323(4.2.1))
be within +-10% unless a separate calibration chart or graph is provided
with the instrument. If a calibration chart is provided, values within
+-20% are acceptable. During calibration, photon dose rate instrument
overload response should be tested by exposing the instrument to a
radiation field whose intensity is 2 to 10 times the maximum range of
the instrument. During this exposure, instrument readings shall remain
full scale. Alternately, some other indication that signifies overload
conditions is acceptable.
Instruments consisting of separate detectors and count-rate
meters/scalers may be calibrated using a suitable pulser to test/adjust
the rate meter/scaler over its entire range. This should be followed by
testing the detector at several selected reference values with an
appropriate source or sources. Calibration with the sources should be
performed on the scales most commonly used in the field. In the case of
contamination monitors or other energy-dependent detectors, the
calibration should include several sources covering an energy range
typical of field conditions. If existing documentation shows that
detectors will operate independently of a specific readout
(interchangeability) and will not cause measurements to exceed the
accuracy goal of 10% (recommended goal +-5%), the detectors and
count-rate meters/scalers may be calibrated independently.
When an instrument is intended to be used outside of its design
parameters, or when it is desirable to use the instrument under
conditions that are considerably different from standard conditions, a
special calibration should be performed (RCM 562.6). Variations in
conditions such as radiation energy, temperature, pressure, humidity or
geometry may require a special calibration. Special calibrations may be
performed by determining correction factors to be applied to a routinely
calibrated instrument or by adjusting the instrument to read correctly
under the special conditions. When an instrument is adjusted, it should
be clearly labeled to ensure that it is used only under the special
conditions and not for routine measurements (RCM 562.6). Any special
instructions, such as unique functional tests, should also be provided.
When correction factors are used, the user should be provided with the
appropriate graphs or specific factors for field conditions. Some of the
correction factors (e.g., temperature, energy) may be available from
type testing, but it should be determined that the variation among
instruments is small enough that such data is valid when applied to a
specific instrument. Appropriate guidance from ANSI N323 on special
calibrations should be used.
Section IV, Subsection C - Functional Tests
As part of maintaining instrument calibration, instruments "shall" be
routinely tested for operability (e.g., source checks, battery tests,
etc.) (10 CFR 835.401(c)(4) and RCM 551.2).
The routine functional tests should be detailed in the instrument-use
procedures and should include, as a minimum: general condition; battery
condition; verification of calibration; background readings; and other
tests (high voltage, zero setting, alarm functions, etc.) as applicable
to the instrument. Functional tests also include the response check and
source check. The performance of field tests should be appropriately
documented.
Instrument response shall be checked (RCM 551.5) prior to each use when
they are used on an intermittent basis and daily during continuous use.
Readings should be taken on each scale or decade used during normal
operations (ANSI N323(4.6)). The operator should establish a reference
reading for the check source immediately after calibration or upon
receipt in the field. If reference sources are at fixed locations in the
field, the reference readings should be established immediately after
the instrument is delivered to the field. The test readings for the
check source shall (ANSI N323(4.6)) be within ñ20% of the reference
reading. If the reading is outside of this range, the instrument should
be taken out of service and returned for recalibration and testing (RCM
551.5).
Section IV, Subsection D - Maintenance
D. Maintenance
Preventive maintenance "shall" be performed periodically (at least
annually) to ensure that the instruments continue to meet the required
accuracy for field measurements (10 CFR 835.401(c)(1) & RCM 563).
Certain tests should be repeated because aging or replacement of
components may affect the instrument's performance (ANSI N323(3)). Tests
that should be repeated at a frequency determined by the facility, or
after maintenance that may affect performance, are:
-- Range, sensitivity, linearity, detection limit, and response to
overload conditions (these may be accomplished through a routine
calibration);
-- accuracy and coefficient of variation (these may be accomplished
through a routine calibration); and
-- on a case-by-case basis, if the nature of the maintenance should
provide for doubt of the validity of any other performance
specifications such as energy dependence, temperature, humidity,
etc.; then tests for those particular attributes should be
performed.
All preventive and corrective maintenance should be performed using
components and procedural recommendations at least as stringent as those
specified by the manufacturer of the instrument (RCM 563.2). If the
manufacturer does not provide routine maintenance procedures, a
procedure should be written and approved by staff and management in the
organization performing the maintenance. Replacement components should
be manufacturer-approved or equivalent. Repairs made using components
which are not technically equivalent constitute an instrument
modification and should be considered to render invalid any type tests
made on the instrument model as applied to the specific instrument.
Instruments that have been modified for special purposes should have
their performance tested and documented following methods in ANSI
N42.17A prior to their calibration and issuance for field use. If the
user can document that the modifica- tions or substituted components
will not affect the instrument performance, additional ANSI N42.17A
testing is not required.
Section IV, Subsection E - Accuracy/Quality Assurance
E. Accuracy/Quality Assurance
Quality assurance and quality control activities in a radiation calibration
laboratory include specific activities to establish and maintain the
reference radiation field to assure accurate instrument calibration.
Requirements for the possession and maintenance of calibration standards,
accuracy of reference radiation fields, and for assessments of calibration
quality are given in this section.
1. Calibration Standards
The calibration laboratory should possess and maintain appropriate
radiation and non-radiation standards to achieve reliable operation.
This will involve the use of standards with both implied and
demonstrated consistency to national standards, as well as a laboratory
hierarchy of standards and system of constancy checks. The calibration
laboratory should participate in a program to demonstrate consistency
for all of its reference radiation standards through calibrations with
NIST or an intercomparison program with other DOE, national or
international laboratories.
The laboratory should (ANSI N323(5.1)) have and maintain secondary or
tertiary radiation measurement standards (laboratory standards) to cover
the range of calibrations performed. For tertiary laboratories,
calibration standards must themselves be calibrated against a secondary
or primary standard. The laboratory standards should be used only for
calibration of working standards. A working standard should be used in
lieu of a laboratory standard for routine calibration operations. For
example, if a laboratory sends an ion chamber to the National Institute
of Standards and Technology (NIST) and uses the NIST-calibrated ion
chamber to calibrate the laboratory's calibration source, the
NIST-calibrated ion chamber is considered to be the laboratory standard.
The laboratory should then calibrate a second ion chamber using their
calibration source. This second ion chamber is the working standard and
should be used for routine calibrations and the ion chamber calibrated
at NIST should be set aside and maintained as the laboratory standard.
The laboratory radiation standards are used to establish the reference
radiation fields. Radioactive sources used as radiation standards should
be corrected for radioactive decay. For non-radiation quantities (e.g.,
temperature, humidity, pressure, voltage, current, etc.), the facility
may use standards based on traceability to NIST.
A secondary laboratory shall have a barometer and thermometer capable of
+-1% accuracy (NIST 812 (Part A, 4.2)). For secondary laboratories,
these (barometer and thermometer) may be calibrated by comparison with a
tertiary or higher level standard. A calibrated hygrometer capable of
monitoring the full range of relative humidity within which the
laboratory operates should also be available.
2. Reference Radiation Field Requirements
The calibration laboratory should establish its reference radiation
fields in a manner that provides demonstrated consistency with national
standards. If the laboratory is operating as a secondary laboratory, it
should demonstrate consistency of reference radiation fields with
national standards to the values shown in Table 1 (NIST 812 (Part B1,
5.4; Part B2, 5.4; Part B3, 5.5; Part B4, 5.3; Part B5, 5.2)). If the
laboratory is operating as a tertiary level facility, the values in
Table 1 apply to the interaction with a secondary laboratory.
Stated accuracy for the reference radiation field should include an
analysis of all uncertainties, including uncertainties in positioning of
standards, uncertainties in environmental corrections, etc.
TABLE 1. Reference Field Accuracies (a) and Quantities
Radiation Type Accuracy Quantity
-------------------------------------------------------
Gamma +-5% Exposure (b)
X-ray +-5% Exposure (b)
Neutron +-10% Fluence
Beta +-10% Shallow Dose
Alpha contamination +-5% Emission/unit area
Beta contamination +-5% Emission/unit area
(a) Accuracies are for dose rates or activities greater than 10 mR/h,
10 mrem/h, or 3 x 10-2 Ci/cm2 (100 micro-Gy/h, 100 micro-Sv/h,
or 103 Bq/cm2).
(b) or Air Kerma
3. Maintenance of Standards
The laboratory's quality control procedures should be designed to
discover undesired changes in equipment performance, upon which the
quality of calibrations depends. The procedures should also be designed
to detect changes in the quality of the services performed. The quality
control methods and their frequency of use should be specified in the
laboratory's procedures. The uses of redundant instrumentation,
constancy checks, control charts, detailed procedures, and redundant
calibrations are the major quality assurance/quality control activities.
All reference fields and measurement standards should be subjected to a
system of constancy checks. This includes not only the reference
radiation standards but also thermometers, timers, voltmeters,
barometers, pressure gauges, and other measuring devices used during the
calibration process. For instrument testing, constancy checks should
extend to radio frequency field intensity and other parameters.
Constancy checks are performed by comparing indications between two or
more measuring standards. The results of these measurements should be
documented on control charts, and the quality control program should
indicate when such comparisons will require additional investigation.
The required investigation or other activity should also be indicated.
4. Assessments
The activities within the calibration laboratory "shall" be audited such
that, over a three year period, all functional elements are assessed,
including program content and implementation (10 CFR 835.102, RCM
134.1). All records, calibration reports, constancy checks, procedures,
and other facility documents should be audited at least every two years
by an independent group and documented. The audit should ensure that
procedures are current and that actual practices are consistent with the
procedures. The facility should also participate in a periodic
proficiency test or an intercomparison program.
Instrument calibration quality should be audited by supervisory
personnel periodically (not less than quarterly) and documented. Audits
should consist of randomly selected instrument recalibrations and
observations of calibrations.
Section IV, Subsection F - Laboratory Documentation
F. Laboratory Documentation
The calibration laboratory should maintain three important sets of
documentation: (1) the laboratory protocol; (2) the laboratory records; and
(3) the calibration records. Historical records should be maintained which
detail any changes or revisions in procedures or protocols. The laboratory
protocol describes the laboratory operations, i.e., what the laboratory is
expected to do and how it is expected to do it. This documentation should
also include the detailed calibration procedures for each instrument
routinely calibrated. The laboratory records, on the other hand, is that
set of records which documents the actual activities of the laboratory.
Finally, the calibration records is that set of records which documents the
maintenance, calibration, and testing of each instrument and source used.
1. Laboratory Protocol
Each DOE laboratory should have a written protocol for calibration of
portable survey instruments (NIST 812 (Part 5.1)). Each page of the
protocol should indicate the date of inception or revision. The
laboratory protocol should include the following:
-- A statement of the laboratory's work scope, including all radiation
types, energies, and intensities used for calibrations;
-- a statement of requirement regarding acceptance of instrumentation
for calibration (The requirement regarding instruments that are
contaminated, in need of repair, or of a particular type should be
stated.);
-- a statement of the laboratory's procedures to assure the specified
accuracy, in terms of deviations from a national standard, for the
reference fields;
-- a method of documenting the model, calibration date, and serial
number of each critical piece of equipment that is used in any
calibration;
-- the procedure for calibrating each piece of laboratory support
equipment (e.g., voltmeters, thermometers, pulsers, etc.) and a
statement of the conditions under which recalibration is to be
performed;
-- a fully documented procedure for each type of instrumentation
calibrated;
-- an assessment of the uncertainty associated with each calibration
procedure;
-- an example of a completed instrument calibration report, including
a statement of the accuracy to which the reference value of the
radiation field is known;
-- the procedure or method for auditing calibration data and approving
reports; and
-- the procedure to ensure the security of calibration records.
2. Laboratory Records
DOE requirements for facility records are stated in RCM 761 and
additional information can be found in ANSI N13.6, "American National
Standard Radiation Protection Practice for Occupational Radiation
Exposure Records Systems" (ANSI, 1989c). Specific information for
calibration laboratories is provided below. A comprehensive and
readily available record system "shall" be maintained (10 CFR 835.703(d)).
The essential elements of a record system are:
-- A full history (purchase, modification, maintenance, etc.) and
calibration data, including certificates, for all standards and
applicable calibration equipment (RCM 761.1 and NIST Special
Publication 812);
-- all procedures used for providing calibration services (RCM 761.1);
-- records shall be maintained detailing the training of all
calibration facility operating staff and supervisory personnel (RCM
761.1);
-- a history of the training and educational experience of all
calibration facility operating staff and supervisory personnel;
-- records "shall" be maintained to document the results of internal
audits and other reviews of program content and implementation (10
CFR 835.704(c) and RCM 743);
-- an inventory of all standards and calibration equipment, including
purchase specifications and acceptance test records;
-- the model and serial number or other unique identification for
every item of instrumentation calibrated and the date that the
calibration was performed;
-- information essential to the analysis and reconstruction of the
calibration of a specific item of instrumentation;
-- a record of routine quality control actions and any resultant
control charts;
-- copies of all calibration records issued (see next section);
-- the results of all proficiency testing; and
-- records of all maintenance, modification, special tests, and repair
of instruments (RCM 761.4 & 762).
All records of data should include the identity of the individual who
collected the data on which the record is based and the record's date of
inception. All records "shall" be retained until final disposition is
authorized by DOE (10 CFR 835.701(b) and RCM 712.3 & 774.1).
If calibration data are stored in a computer, the laboratory protocol
should specify how backup is provided (e.g., data protection
procedures). Archival tape, diskettes, microfilm, hard copy, etc., are
examples of methods of archiving data. The method selected will
normally depend on the laboratory's record system and volume of data.
3. Instrument Calibration Records
A record "shall" (10 CFR 835.703(d)(1) & RCM 761.1) be maintained for
results of calibration and maintenance performed for each instrument.
This includes records of functional tests (operational checks) (RCM
761.3). Maintenance histories and repair and modification data "shall"
(10 CFR 835.703(d)(1) and RCM 761.4 & 762) be maintained for each
instrument. Both as-found data and data on the final calibration
results for the instrument (after adjustments, if required) shall be
included in the record (RCM 761.1). The record shall be dated and shall
identify the individual performing the work on the instrument (RCM
761.1). The record should be filed with previous records on the same
instrument in accordance with ANSI N13.6. Each instrument shall (ANSI
N323 (4.5)) be labeled with the following information, which should also
be in the calibration report:
-- Date of most recent calibration (RCM 562.7);
-- initials or other specific identifying mark of calibrator;
-- energy correction factors, where required;
-- graph or table of calibration factors, where necessary, for each
type of radiation for which the instrument may be used (including
the relationship of the scale reading to the measurement units, if
the units are not on the scale);
-- instrument response to an identified check source (if provided by
the calibrator);
-- unusual or special use conditions or limitations (RCM 562.6); and
-- date that primary calibration is again required (RCM 562.7) (not
required on calibration report if a documented recall system is
maintained).
All calibration reports should contain a statement of the uncertainty of
the calibration. Alternatively, when calibrations are performed
repeatedly on the same model, a generic analysis of uncertainty may be
maintained. This should include an analysis based on random checks of
calibrated instruments.
4. Instrument Location
A system for tracking the location of portable survey instruments and
for recalling those instruments for recalibration shall be established
(ANSI N323). The location of portable survey instruments should be
known by the calibration staff or by some identifi- able group assigned
with that responsibility. Because instruments may incorporate or be
accompanied by an accountable source, instrument tracking may be
required as part of the source-control program.
Section IV, Subsection G - Laboratory, Equipment, and Staff
G. Laboratory, Equipment, and Staff
The location, design, and use of the laboratory for calibrations should
ensure that conditions within the laboratory will not affect calibration
quality (RCM 564.1). In addition, the laboratory "shall" be designed to
keep worker exposures ALARA in compliance with 10 CFR 835.1002(a). The
laboratory should also have an appropriate selection of calibration
equipment and should be operated with a properly organized and trained
staff.
1. Laboratory
The effect of external conditions on the internal environment of the
calibration laboratory should be considered in selecting the facility
site. The laboratory should be sited away from, or otherwise isolated
from, sources of mechanical vibration and shock, sources of electrical
and electromagnetic interference, and other potential sources of
interference with the proper calibration of instrumentation. If such
potential sources exist, the laboratory should have documentation that
demonstrates an absence of adverse effects on calibration accuracy.
The electrical power should be appropriate for the equipment used,
suitably stable, and free of switching surges and significant line
noise. When necessary, local auxiliary voltage stabilizers, filters,
and uninterruptable power supplies should be provided.
The laboratory environment should be con- trolled to ensure that
environmental conditions do not affect the calibration quality.
Appendix B shows the standard conditions that should be established for
the laboratory.
Calibration areas should not be used for storage of instruments,
equipment, or sources. Such storage may lead to variable scatter or
abnormal background radiation conditions.
For secondary laboratories, free-space geometry should be achieved for
photon and neutron instrument calibration. The distance to scattering
objects from the source and from the detector should be at least twice
the distance between the detector and source. The scattering conditions
in the laboratory should be known, and where scattering contributes
significantly to instrument readings, the conditions should be included
in stating the value of the radiation field for all detector positions
used for calibration purposes. For routine calibrations at tertiary
laboratories, it may not be necessary to establish free-space
calibration conditions. Calibration wells or calibration boxes may be
suitable. For all calibration geometries the effect of scattering and
attenuators on calibration accuracy should be evaluated and documented.
Instrument calibration assemblies shall (ANSI N323(5.2)) be mechanically
precise to ensure that positioning uncertainties of either instruments
or radiation sources do not affect the radiation field values by more
than +-2%. A sufficient range of radiation fields should be available to
satisfy instrument calibration requirements.
The calibration laboratory working conditions should not cause excessive
radiation exposure of personnel. Personnel exposure shall be kept ALARA
(10 CFR 835.101(c)) and should in no case, under normal operating
conditions, exceed administrative control levels established for the
site. To meet this condition, personnel shielding, remote instrument
reading and positioning facilities, automatic source handling
mechanisms, and other mechanical or remote operations are recommended.
All areas in the laboratory should be properly posted.
2. Instrument Calibration Equipment
Instruments should be calibrated with appropriate standards of known
hierarchy derived from national standards. Working standards derived
from secondary or tertiary standards should be used for all routine
operations. Calibrations shall (ANSI N323 (5.1)) be conducted in one of
the following ways:
a. Compare the response of an instrument to the calibration points of
a NIST source and use this reproducible instrument to calibrate
points from the user's source. The transfer calibration should use
a calibration curve for the transfer instrument taken with the
national or secondary source over a range that covers both the
national or secondary source measurement and the user source
measurement;
b. Perform a calibration of a user's transfer standard with a national
or secondary standard source, followed by calibration of user's
reference source with the same transfer instrument. The transfer
instrument should have a reproducibility of +-2%(ANSI N323(5.1));
and
c. Where no national standard exists, as in the case of specific
energies or unusual sources, establish a standard source or
instrument with documented empirical and theoretical output or
response characteristics.
A calibration source (or sources, preferably) should emit radiation at a
rate sufficient to reach the full scale of any instrument to be
calibrated. If the source is a radionuclide, the half-life should be
long, preferably greater than several years, to minimize corrections and
uncertainties. The uncertainty of reference field calibration should be
no greater than +-5% with respect to national standards for photons and
for alpha/beta contamination sources, and +-10% for beta particles and
neutrons as noted in Table 1. Appendix C lists recommended reference
sources for calibration and standards, or publications where they are
described in more detail.
3. Calibration Staff Qualifications
The calibration laboratory manager should have a position in the
organizational structure that ensures that they have the authority to
conduct operations free from any influence that could adversely affect
the quality or impartiality of the services offered. This individual
should have a minimum of a bachelor's degree in physics, engineering,
health physics, or radiological physics; and a graduate degree in one of
these or a closely related scientific field is highly desirable. This
individual should understand the laboratory protocol, be fully
responsible for assuring that it is being followed, and should, at least
annually, evaluate staff competence and the need for training.
The individual(s) in charge of day-to-day operation of the laboratory
should have at least three years of practical experience in radiation
measurement, including calibration of radiation instrumentation. In
smaller operations, the manager may also be in charge of day-to-day
operations.
4. Calibration Staff Training
All staff employed in calibration work "shall" be trained in radiation
safety prior to receiving occupational exposure (10 CFR 835.901(a) & RCM
621). Further, all staff employed in calibration work "shall" have
appropriate training as radiological workers and in job-specific
procedures (10 CFR 835.902 and RCM 631.2). Job-specific procedures
include such items as, calibration procedures, facility operations, and
correct operation of calibrated instruments. Staff shall receive
Radiological Worker I training (RCM 632.1). In some facilities
Radiological Worker II training or a combination of Radiological Worker
I training with supplemental High Radiation Area training will be
required because of the need to enter high radiation areas (10 CFR
835.901 & 902 and RCM 631 - 633). Key staff members should receive
Radiological Worker II training so that they can participate in possible
recovery operations (e.g., a stuck source) where their knowledge may be
critical. Although radiation protection personnel will be responsible
for performing such recovery operations, it may be beneficial for a
member of the calibration staff who is fully familiar with the layout of
the laboratory and the types, characteristics, and locations of sources
within the laboratory, to assist in the recovery operations.
Apart from radiological safety training, the staff should receive
training on the theory of radiation detectors, interaction of radiation
with matter, basic statistics, maintenance of records, quality
assurance, and other topics related to the safe and efficient operation
of calibration equipment.
Section V - References
V. REFERENCES
(AEC, 1954) Atomic Energy Act of 1954, as amended. Public Law 83-703
(68 Stat. 919), Title 42 U.S.C. sec. 2011.
(ANSI, 1983) American National Standards Institute. 1983. "American
National Standard Radiation Protection Instrumentation Test and
Calibration." ANSI N323-R1983. New York, New York.
(ANSI, 1989a) American National Standards Institute. 1989. "Performance
Specifications for Health Physics Instrumentation - Portable
Instrumentation for Use in Normal Environmental Conditions." ANSI
N42.17A-1989. New York, New York.
(ANSI, 1989b) American National Standards Institute. 1989. "Performance
Specifications for Health Physics Instrumentation - Portable
Instrumentation for Use in Extreme Environmental Conditions." ANSI
N42.17C-1989. New York, New York.
(ANSI, 1989c) American National Standards Institute. 1989. "American
National Standard Radiation Practice for Occupational Radiation Exposure
Records Systems." ANSI N13.6-R1989. New York, New York.
(DOE, 1984) U.S. Department of Energy. 1984. "Environmental Protection,
Safety, and Health Protection Standards." DOE Order 5480.4. Washington,
D.C.
(DOE, 1992) U.S. Department of Energy. 1992. "Radiation Protection for
Occupational Workers." DOE Order 5480.11. Washington, D.C.
(DOE, 1993a) U.S. Department of Energy. 1993. "Occupational Radiation
Protection." 10 CFR 835, 58 FR 65458, Federal Register, Vol. 58, No. 236:
December 14, 1993. Washington, D.C.
(DOE, 1993b) U.S. Department of Energy. 1993. "Procedural Rules for DOE
Nuclear Activities." 10 CFR 820, 58 FR 43680, Federal Register, Vol. 58,
No. 157: August 17, 1993. Washington, D.C.
(DOE, 1994) U.S. Department of Energy. 1994. "Radiological Control Manual."
DOE/EH-0256T. Washington, D.C.
(ISO, 1979) International Organization for Standardization. 1979. " X
and Gamma Reference Radiation for Calibrating Dosemeters and Dose
Ratemeters and for Determining Their Response as a Function of Photon
Energy." ISO 4037-1979(E). Zurich, Switzerland.
(ISO, 1985) International Organization for Standardization. 1985.
"Reference Data Radiations for Calibrating Dosemeters and Dose Ratemeters
and for Determining Their Response as a Function of Beta Radiation
Energy." ISO 6980-1985. Zurich, Switzerland.
(ISO. 1988a) International Organization for Standardization. 1988.
"Evaluation of Surface Contamination - Part 2: Beta-Emitters -
Beta-Emitters (Maximum Beta Energy Greater Than 0.15 MeV) and
Alpha-Emitters." ISO 7503-1-1988. Zurich, Switzerland.
(ISO, 1988b) International Organization for Standardization. 1988.
"Evaluation of Surface Contamination - Part 2: Tritium Surface
Contamination." ISO 7503-2-1988. Zurich, Switzerland.
(ISO, 1989) International Organization for Standardization. 1989.
"Neutron Reference Radiations for Calibrating Neutron-Measuring Devices
Used for Radiation Protection Purposes and for Determining Their
Response as a Function of Neutron Energy." ISO 8529-1989. Zurich,
Switzerland.
(ISO, 1991) International Organization for Standardization. 1991.
"Reference Sources for the Calibration of Surface Contamination Monitors
- Beta-Emitters (Maximum Beta Energy Greater Than 0.15 MeV) and
Alpha-Emitters." ISO 8769-1991. Zurich, Switzerland.
(NBS, 1989) National Bureau of Standards. 1989. "Calibration and
Related Measurement Services of the National Bureau of Standard."
Special Publication 250. Washington, D.C.
(NCSL, 1989) National Conference of Standards Laboratories. 1989.
"Recommended Practice RP-1, Establishment and Adjustment of Calibration
Intervals." Boulder, Colorado.
(NIST, 1991) Eisenhower, E. H., editor. 1991. "Criteria for the Operation
of Federally-Owned Secondary Calibration Laboratories (Ionizing
Radiation)." National Institute of Standards and Technology, Special
Publication 812. U.S. Department of Commerce. Washington, D.C.
Section VI - Supporting Documents
Heaton, II, H. T., and G. T. Lalos. 1983. "Calibration Handbook:
Ionizing Radiation Measuring Instruments." Naval Surface Weapons Center.
White Oak, Maryland.
International Atomic Energy Agency. 1971. "Handbook on Calibration of
Radiation Protection Monitoring Instruments." IAEA Technical Report 133.
Vienna, Austria.
U.S. National Bureau of Standards. 1981. "Requirements for an Effective
National Ionizing Radiation Measurements Program." NBS Special
Publication 603. U.S. Department of Commerce. Washington, D.C.
Appendix A - Manual Cross-Reference
Appendix A
10 CFR 835, Implementation Guide, and DOE Radiological Control
Manual Cross-Reference
10 CFR 835 Implementation Guide Radiological Control Manual
---------------------------------------------------------------------------
835.101(c) III & IV.G.1 -
835.102 IV, & IV.E.4 134.1
835.401(c)(1) III, III.B, III.D, IV, 562.3, 562.8, & 563
IV.B & IV.D
835.401(c)(2) III & III.A 562.1
835.401(c)(3) III & III.A 562.4
835.401(c)(4) III, III.C, IV, & IV.C 551.2 & 551.5
835.403(b) III 551
835.701(b) IV.F.2 712.3 & 774.1
835.703(d)(1) IV, & IV.F.2-3 761 & 762
835.704(a) IV 725
835.704(c) IV.F.2 743
835.704(e) IV 751.2
835.901(a) IV.G.4 621 & 632
835.902 IV.G.4 631, 632, & 633
835.1002(a) IV.G -
Appendix B - Standard Test or Calibration Conditions
Appendix B
Standard Test or Calibration Conditions
(Source: ANSI N42.17A)
Parameter Standard Values
-----------------------------------------------------------------
Warmup time <= 10 minutes
Relative humidity Ambient +-10%, not to exceed 75%
Ambient temperature 20 deg. C to 24 deg. C
Atmospheric pressure 70 to 106 kPa
Line voltage (a) Nominal +-1%
Frequency (a) 60 Hz +-0.5 Hz
AC power supply waveform (a) Sinusoidal with total harmonic
distortion <= 5%
Background ambient photon <=2.5% of the full scale of the range
(external) or decade under test, but normally (b)
should not exceed 50 micro-rad/h
(0.5æGy/h), referenced to air
Non-ionizing electromagnetic Less than 50% of the lowest value
field external origin that causes interference
Magnetic induction of external Less than twice the induction due to
earth's magnetic field the earth's magnetic field
Controls Set for normal operation according to
manufacturer's recommendations
Contamination by radionuclides Should not exceed levels found in RCM
Table 2-2. (c)
Reference point Geometrical center of detector
(a) Applicable only to AC-powered instruments.
(b) For ranges <= 2 mrad/h (0.02 mGy/h), shielding may be required.
(c) Contamination in calibration areas should be kept as low as
practicable.
Appendix C - Reference Sources for Calibration
Appendix C
Reference Sources for Calibration
Radiation Type Reference Source Reference
----------------------------------------------------------------------
DOSE RATE
---------
Gamma 137Cs(a), 60Co(a) and 241Am ISO-4037-1979(E)
X-ray M30(a), H50(a), H150(a), NBS Spec. Pub. 250-1989
H200(a), H250(a), H300(a), M150,
and S60
X-ray 16, 24, 34, 43, 58, 78 ISO-4037-1979(E)
(K fluorescence) and 100 keV
Neutron 252Cf(a), 241Am-Be(a), ISO-8529-1989
and 252Cf+D2O moderator
Beta 90Sr-90Y(a) and 204Tl(a) ISO-6980-1985
SURFACE CONTAMINATION
---------------------
Alpha 241Am, 230Th(a) and 239Pu(a) ISO-8769-1991
Beta 90Sr- 90Y(a), 14C, 147Pm, 36Cl, ISO-7503-1-1988a
204Tl(a), 106Ru-106Rh, U-Nat and U-Dep
3H ISO-7503-2-1988b
(a) ANSI N42.17A-1989
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Suggested Specific Word Changes:
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Contact: Steve G. Zobel, (301) 903-2305