ASTM C1269-97(2003)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:C1269–97(Reapproved2003)
Standard Practice for
Adjusting the Operational Sensitivity Setting of In-Plant
Walk-Through Metal Detectors
This standard is issued under the fixed designation C1269; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Nuclear regulatory authorities require personnel entering designated security areas to be screened
for concealed weapons. Additionally, in security areas containing specified quantities of special
nuclear materials, personnel exiting the facility are required to be screened for metallic nuclear
shielding material. Walk-through metal detectors are widely used to implement these requirements.
Nuclear regulatory authorities usually specify an assortment of metal detector test objects that must
all be detected by walk-through metal detectors. This practice provides a procedure for adjusting the
operational sensitivity setting to the lowest setting necessary to detect the least likely to-be-detected
test object in its least likely to-be-detected orientation while passing through the detection zone in the
weakest known detection path. All other test objects will then be detected at this sensitivity setting
anywhere in the detection zone.
1. Scope 1.7 The values stated in SI units are to be regarded as
standards. The values given in parentheses are for information
1.1 This practice covers a procedure for adjusting the
only.
operational sensitivity of in-plant walk-through metal detec-
tors. Performance of this procedure should result with in-plant
2. Referenced Documents
walk-through metal detectors being adjusted to an initial
2.1 ASTM Standards:
operational sensitivity setting suitable for performance testing.
C1238 Guide for Installation of Walk-Through Metal De-
1.2 This practice does not set test object specifications or
tectors
specify specific test objects. These should be specified by the
C1270 Practice for Detection Sensitivity Mapping of In-
regulatory authority.
Plant Walk-Through Metal Detectors
1.3 This practice uses information developed by Practice
C1309 Practice for Performance Evaluation of In-Plant
C1270, or an equivalent procedure, which identifies the critical
Walk-Through Metal Detectors
test object (from a specified set of test objects), its critical
F1468 Practice for Evaluation of Metallic Weapons Detec-
orientation, and the critical test path through the detection
tors for Controlled Access Search and Screening
zone. In the case of Practice C1270, the information is found
on the detection sensitivity map(s) for each in-plant walk-
3. Terminology
through metal detector.
3.1 Definitions of Terms Specific to This Standard:
1.4 This practice is one of several developed to assist
3.1.1 clean-tester, n—a person who does not carry any
operators of nuclear facilities with meeting the metal detection
extraneous metallic objects that would significantly alter the
performance requirements of the regulatory authorities (see
signal produced when the person carries a test object.
Appendix).
3.1.1.1 Discussion—Smaller test objects require more com-
1.5 This standard practice is neither intended to set perfor-
plete elimination of metallic objects. By example but not
mance levels nor limit or constrain technologies.
limitation, such extraneous metallic objects may include:
1.6 This practice does not address safety or operational
metallicbeltbuckles,metalbuttons,cardiacpacemakers,coins,
issues associated with the use of walk-through metal detectors.
metal frame eyeglasses, hearing aids, jewelry, keys, mechani-
cal pens and pencils, shoes with metal shanks or arch supports,
This practice is under the jurisdiction of ASTM Committee C26 on Nuclear
Fuel Cycle and is the direct responsibility of Subcommittee C26.12 on Safeguard
Applications. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Feb. 10, 2003. Published February 2003. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1994. Last previous edition approved in 1997 as C1269 – 97. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/C1269-97R03. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C1269–97 (2003)
metallic surgical implants, undergarment support metal, metal
zippers, etc. In the absence of other criteria, a clean tester
passing through a metal detector shall not cause a disturbance
signal greater than 10 % of that produced when carrying the
critical test object through the detector. Test objects requiring
more complete elimination of extraneous metal to obtain less
than 10 % signal disturbance.
3.1.1.2 Discussion—The tester shall have a weight between
50 to 104 kg (110 to 230 lb) and a height between 1.44 to 1.93
m (57 to 75 in.). Should a given detector be sensitive to body
size because of design or desired sensitivity, the physical size
of testers should be smaller and within a narrower range.
3.1.1.3 Discussion—It is recommended that the clean tester
be surveyed with a high sensitivity hand-held metal detector to
ensure that no metal is present.
3.1.2 critical orientation—the orthogonal orientation of a
test object that produces the smallest detection signal or
weakest detection anywhere in the detection zone; the orthogo-
nal orientation of a test object that requires a higher sensitivity
setting to be detected compared to the sensitivity settings
NOTE 1—Numbers are sensitivity setting values for a hypothetical
required to detect the object in all other orthogonal orienta-
detector. The numbers represent the lowest sensitivity setting at which the
tions. See Fig. 1 for handgun orientations
object was detected ten out of ten consecutive test passes through the
indicated test path.
3.1.2.1 Discussion—Critical orientations are determined by
FIG. 2 Example of Detection Sensitivity Map
testing using a mapping procedure such as described in
Practice C1270.
3.1.2.2 Discussion—The term critical orientation can be
applied in two ways. Critical orientation can refer to the worst
case orthogonal orientation in a single test path or the worst
case orthogonal orientation for all the test paths (the entire
detection zone).The two are coincident in the critical test path.
3.1.3 critical sensitivity setting, n—the lowest sensitivity
setting of a detector at which the critical test object in its
critical orientation is consistently detected (10 out of 10 test
passes) when passed through the detection zone on the critical
test path.
3.1.4 critical test element, n—see test element.
3.1.5 critical test object, n—see test object.
3.1.6 critical test path, n—the straight-line shortest-course
path through the portal aperture, as defined by an element on
the detection sensitivity map, that produces the smallest
detection signal or weakest detection for the critical test object
in its critical orientation. (see Figs. 2 and 3)
FIG. 3 3-D View of Detection Zones and Test Grid
3.1.7 detection sensitivity map, n—(see Fig. 2) a depiction
of the grid used to define test paths through the detection zone
with each element of the grid containing a value, usually the
sensitivity setting of the detector, that is indicative of the
detectability of the test object.
3.1.7.1 Discussion—These values are relative and describe
the detection sensitivity pattern within the detection zone for
the specific test object. The values are derived by identically
FIG. 1 Six Standard Orthogonal Orientations for a Handgun testing each defined test path using a specific test object in a
C1269–97 (2003)
single orthogonal orientation. The value is usually the mini- 3.1.18 test object, n—metallic item meeting dimension and
mum sensitivity setting of the detector that will cause a material criteria used to evaluate detection performance.
consistent alarm (10 out of 10 test passes) when the test object
3.1.18.1 critical test object—the one test object out of any
is passed through the detection field.Appendix X2 is a sample
given group of test objects that, in its critical orientation,
form for a potential detection sensitivity map configuration.
produces the weakest detection signal anywhere in the detec-
3.1.8 detection zone—thevolumewithintheportalaperture. tionzone.Thegroupreferredtoconsistsofoneormoreobjects
that are to be detected at the same detector setting.
3.1.9 detector, n—see walk-through metal detector.
3.1.18.2 Discussion—Depending on the particular detector,
3.1.10 element, n—see test element.
some orientation sensitive test objects may have orientations at
3.1.11 grid, n—see test grid.
different locations in the detection zone that result in near
3.1.12 grid element, n—(1) a single block on a detection
critical sensitivity settings. Hence, care must be taken in
sensitivity map; (2) the rectilinear volume through the detec-
determining the critical test object, its critical orientation, and
tion zone defined by coincident elements of identical grid
the critical test path.
works placed on either side of the portal aperture. (see Figs. 2
3.1.18.3 shielding test object—a test object representing
and 3)
special nuclear material shielding that might be used in a theft
3.1.12.1 test path, n—as defined by an element on a
scenario.
detection sensitivity map, a straight-line shortest-course path
3.1.18.4 Discussion—It is usually a metallic container or
through the detection zone of a detector undergoing mapping,
metallic material configured as a credible gamma-radiation
detection sensitivity, or detection sensitivity verification test-
shield for a specific type and quantity of special nuclear
ing. (see Fig. 3)
material. The object is specified by a regulatory authority or is
3.1.13 in-plant, adj—installed in the location, position, and
based on the facility threat analysis, or both.
operating environment where the device will be used.
3.1.18.5 weapon test object, n—a handgun(s) or simulated
3.1.14 orthogonal orientation—as used in this practice,
handgun designated by or satisfying the regulatory authority
orthogonal orientation refers to alignment of the longitudinal
requirement for a weapon test object.
axis of a test object along the xyz axes of the Cartesian
3.1.18.6 Discussion—Care must be taken when selecting or
coordinate system; x is horizontal and across the portal, y is
designing a mock handgun. Simple blocks of metal shaped like
vertical, and z is in the direction of travel through the portal.
a handgun will likely not cause a metal detector to react the
3.1.15 portal, n—see walk-through metal detector. (See
same as it would to the intricate shapes and variable compo-
Fig. 1 for handgun orientations)
nents of a real handgun. Most government agencies use actual
3.1.16 test element, n—(seeFigs.2and3)forthepurposeof
guns for testing.
testing, it is necessary to define discrete and repeatable
3.1.19 walk-through metal detector (detector, portal), n—a
straight-line shortest-course test paths through the detection
free-standing screening device, usually an arch-type portal,
zone. This can be done by using two identical networks (grids)
using an electromagnetic field within its portal structure
made of nonconductive/nonmagnetic material attached across
(aperture) for detecting metallic objects, specifically weapons
the entry and exit planes of the portal aperture so the networks
or metallic shielding material, or both, on persons walking
coincide.Atest object on the end of a probe can then be passed
through the portal.
from one side of the portal aperture to the other side through
3.1.20 walk speed (normal), n—walk speed is between 0.5
corresponding openings, which results in the test object taking
1 1
to 1.3 m/s (1 ⁄2 to 2 ⁄2 steps/s).
a reasonably straight-line shortest-course path through the
3.1.20.1 Discussion—The average casual walk rate is about
detection zone. If the networks are constructed so that they can
1 ⁄4 steps/s.
beputin-placeidenticallyeachtimetheyareused,thenthetest
3.1.20.2 shielding test object, n—see test object.
paths through the detection zone are repeatable over time.
3.1.20.3 weapon test object, n—see test object.
Thus, a test element is the volume of space defined by the
boundaries of two corresponding network openings and it
4. Summary of Practice
represents a straight-line shortest-course path through the
detection zone.
4.1 A clean-tester carries the critical test object in the
critical orientation through the critical test element in the
3.1.16.1 Discussion—On a detection sensitivity map the
normal operating fashion. The metal detector sensitivity is
corresponding networks appear as a rectangular grid with each
adjustedupward,startingfromasettingwherenoalarmsoccur,
element of the grid representing a test path through the
until the lowest sensitivity setting is found where 10 consecu-
detection zone.The element defining the critical test path is the
tive passes result with 10 consecutive alarms. This value is the
critical test element.
initial operational sensitivity setting.
3.1.17 test grid, n—a network of nonconductive/
nonmagnetic material, such as string or tape, can be stretched
5. Significance and Use
across the entry and exit planes of the portal aperture to define
test paths through the portal aperture; the material should not
5.1 Performing this procedure from this practice should
be hygroscopic.
result in a properly adjusted walk-through metal detector
3.1.17.1 Discussion—See Fig. 2 for an example ofa4by9 operating at or near the optimum sensitivity setting for the
element test grid. environment in which it is installed.
C1269–97 (2003)
5.2 This practice determines the lowest sensitivity setting required by schedule or circumstance (for example, equipment
required to detect a specified test object and establishes a moved, repaired or replaced).
sensitivity setting suitable for most operational needs.
10. Test Object
5.3 This practice may be used to establish an initial sensi-
10.1 This practice uses the critical test object from a set of
tivity setting for follow-on procedures that determine credible
test objects specified by the regulatory authority. The critical
values for probability of detection and confidence level, as
test object is determined by in-plant sensitivity mapping (or an
required by regulatory authorities.
equivalent procedure) of each detector. When a detection
6. Precautions
sensitivity map is u
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