ASTM C1270-97(2021)
(Practice)Standard Practice for Detection Sensitivity Mapping of In-Plant Walk-Through Metal Detectors
Standard Practice for Detection Sensitivity Mapping of In-Plant Walk-Through<brk /> Metal Detectors
SIGNIFICANCE AND USE
5.1 A complex set of variables affect metal detection and detection sensitivity. Some physical characteristics of metal objects that influence detection are material composition, shape, surface area, surface and internal electrical and magnetic properties, and finish. The orientation of a test object can greatly influence detection as can the direction and speed or changes in speed while passing through the detection zone. Nearby large metal objects and metal moving in near proximity to a metal detector also affect operation, as do temperature and humidity, and can be a cause for nuisance alarms. Additionally, most currently manufactured walk-through metal detectors have some means for programming the operation of the detector for special conditions or requirements; these variables and the effect they have on the operation of in-plant detectors must be considered if a test program is to be effective. This practice is intended to minimize the impact of these variables on the operation of in-plant detectors by systematically testing the installed detectors in the operating environment with the test object(s) specified by the regulatory authority requirements.
5.2 This practice may be used to determine the critical test object from a group of test objects, its critical orientation, and the critical test path through the detection zone. This information may allow the use of a single test object for setting the operational sensitivity of the detector and performing periodic performance evaluations necessary to ensure a high probability that all test objects in the group are detectible within the capabilities of the detector.
5.3 The detection sensitivity map(s) generated by this practice provides baseline metal detection data for the specified test objects and can serve as a foundation for in-plant walk-through metal detector set-up and performance evaluation testing. The detection sensitivity map(s) may be incorporated into a detector performance test log in suppo...
SCOPE
1.1 This practice covers a procedure for determining the weakest detection path through the portal aperture and the worst-case orthogonal orientation of metallic test objects. It results in detection sensitivity maps, which model the detection zone in terms related to detection sensitivity and identify the weakest detection paths. Detection sensitivity maps support sensitivity adjustment and performance evaluation procedures (see Practices C1269 and C1309).
Note 1: Unsymmetrical metal objects possessing a primary longitudinal component, such as handguns and knives, usually have one particular orientation that produces the weakest detection signal. The orientation and the path through the detector aperture where the weakest response is produced may not be the same for all test objects, even those with very similar appearance.
Note 2: In the case of multiple specified test objects or for test objects that are orientation sensitive, it may be necessary to map each object several times to determine the worst-case test object or orientation, or both.
1.2 This practice is one of several developed to assist operators of walk-through metal detectors with meeting the metal detection performance requirements of the responsible regulatory authority. (See Appendix X2)
1.3 This practice is neither intended to set performance levels, nor limit or constrain operational technologies.
1.4 This practice does not address safety or operational issues associated with the use of walk-through metal detectors.
1.5 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barrie...
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Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C1270 − 97 (Reapproved 2021)
Standard Practice for
Detection Sensitivity Mapping of In-Plant Walk-Through
Metal Detectors
This standard is issued under the fixed designation C1270; 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
nuclearmaterials,exitingpersonnelarerequiredtobescreenedformetallicnuclearshieldingmaterial.
Walk-through metal detectors are widely used to implement these requirements.
Anumber of environmental conditions, architectural and electrical arrangements near the detector,
and detector characteristics affect the detection of metallic objects passing through the walk-through
metal detector. These external effects and detector characteristics are discussed in Practices F1468,
C1269, and Guide C1238. This practice is intended to minimize the effects of these variables on
detector operation by providing the operator with baseline information on the metal detection
sensitivity within the portal aperture, particularly the location of any weak areas of detection.The data
is obtained by mapping the detection zone (volume within the portal) of each detector at its field
location, under normal operating conditions, and using the target test object. The maps, when applied
to detector operation, ensure that the effects of the fixed environmental conditions, architectural and
electrical arrangements, and detector characteristics are taken into account during operational
sensitivity adjustment, performance evaluation, and general operation of detectors.
with very similar appearance.
1. Scope
NOTE 2—In the case of multiple specified test objects or for test objects
1.1 This practice covers a procedure for determining the
that are orientation sensitive, it may be necessary to map each object
weakest detection path through the portal aperture and the
several times to determine the worst-case test object or orientation, or
worst-case orthogonal orientation of metallic test objects. It both.
resultsindetectionsensitivitymaps,whichmodelthedetection
1.2 This practice is one of several developed to assist
zone in terms related to detection sensitivity and identify the
operators of walk-through metal detectors with meeting the
weakest detection paths. Detection sensitivity maps support
metal detection performance requirements of the responsible
sensitivity adjustment and performance evaluation procedures
regulatory authority. (See Appendix X2)
(see Practices C1269 and C1309).
1.3 This practice is neither intended to set performance
NOTE 1—Unsymmetrical metal objects possessing a primary longitu-
levels, nor limit or constrain operational technologies.
dinal component, such as handguns and knives, usually have one
particular orientation that produces the weakest detection signal. The
1.4 This practice does not address safety or operational
orientation and the path through the detector aperture where the weakest
issues associated with the use of walk-through metal detectors.
response is produced may not be the same for all test objects, even those
1.5 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
This practice is under the jurisdiction of ASTM Committee F12 on Security
only.
Systems and Equipment and is the direct responsibility of Subcommittee F12.60 on
Controlled Access Security, Search, and Screening Equipment.
1.6 This international standard was developed in accor-
Current edition approved Jan. 1, 2021. Published February 2021. Originally
dance with internationally recognized principles on standard-
approved in 1994. Last previous edition approved in 2012 as C1270 – 97 (2012).
DOI: 10.1520/C1270-97R21 ization established in the Decision on Principles for the
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1270 − 97 (2021)
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
C1238 Guide for Installation of Walk-Through Metal Detec-
tors
C1269 Practice forAdjusting Operational Sensitivity Setting
of In-Plant Walk-Through Metal Detectors
C1309 Practice for Performance Evaluation of In-Plant
Walk-Through Metal Detectors
F1468 Practice for Evaluation of Metallic Weapons Detec-
tors for Controlled Access Search and Screening
3. Terminology
FIG. 1 Six Standard Orthogonal Orientations for a Handgun
3.1 Definitions of Terms Specific to This Standard:
the worst case orthogonal orientation for all the test paths (the
3.1.1 clean-tester, n—a person who does not carry any
entiredetectionzone).Thetwoarecoincidentinthecriticaltest
extraneous metallic objects that would significantly alter the
path.
signal produced when the person carries a test object.
3.1.1.1 Discussion—By example but not limitation, such
3.1.3 critical sensitivity setting, n—the lowest sensitivity
extraneous metallic objects may include: metallic belt buckles,
setting of a detector at which the critical test object in its
metal buttons, cardiac pacemakers, coins, metal frame eye
critical orientation is consistently detected (ten out of ten test
glasses, hearing aids, jewelry, keys, mechanical pens and
passes) when passed through the detection zone on the critical
pencils, shoes with metal shanks or arch supports, metallic
test path.
surgical implants, undergarment support metal, metal zippers,
3.1.4 critical test element, n—see test element.
etc. In the absence of other criteria, a clean tester passing
3.1.5 critical test object, n—see test object.
through a metal detector shall not cause a disturbance signal
3.1.6 critical test path, n—the straight-line shortest-course
greater than 10 % of that produced when carrying the critical
path through the portal aperture, as defined by an element on
test object through the detector. Test objects requiring very
the detection sensitivity map, that produces the smallest
high sensitivity settings for detection require more complete
detection signal or weakest detection for a test object in its
elimination of extraneous metal to obtain less than 10 % signal
critical orientation (see Figs. 2 and 3).
disturbance.
3.1.1.2 Discussion—The tester shall have a weight between
3.1.7 detection sensitivity map, n—a depiction of the grid
50 to 104 kg (110 to 230 lb) and a height between 1.44 to
used to define test paths through the detection zone, with each
1.93 m (57 to 75 in.). Should a given detector be sensitive to
element of the grid containing a value, usually the sensitivity
body size because of design or desired sensitivity, the physical
setting of the detector, that is indicative of the detectability of
size of testers should be smaller and within a narrower range.
the test object (see Figs. 2 and 1).
3.1.1.3 Discussion—It is recommended that the clean tester
3.1.7.1 Discussion—These values are relative and describe
be surveyed with a high sensitivity hand-held metal detector to
the detection sensitivity pattern within the detection zone for
ensure that no metal is present.
the specific test object. The values are derived by identically
testing each defined test path using a specific test object in a
3.1.2 critical orientation, n—the orthogonal orientation of a
single orthogonal orientation. The value is usually the mini-
test object that produces the smallest detection signal or
mum sensitivity setting of the detector that will cause a
weakest detection anywhere in the detection zone; the orthogo-
consistentalarm(tenoutoftentestpasses)whenthetestobject
nal orientation of a test object that requires a higher sensitivity
is passed through the detection field. Appendix X3 is a sample
setting to be detected compared to the sensitivity setting
form for a potential detection sensitivity map configuration.
required to detect the object in all other orthogonal orienta-
tions. See Fig. 1 for handgun orientations.
3.1.8 detection zone, n—the volume within the portal aper-
3.1.2.1 Discussion—Critical orientations are determined by
ture.
testing using a mapping procedure such as described in this
3.1.9 detector, n—see walk-through metal detector.
practice.
3.1.10 element, n—see test element.
3.1.2.2 Discussion—The term critical orientation can refer
3.1.11 grid, n—see test grid.
to the worst case orthogonal orientation in a single test path or
3.1.11.1 grid element, n—(1) a single block on a detection
sensitivity map; (2) the rectilinear volume through the detec-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
tion zone defined by coincident elements of identical grid
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
works placed on either side of the portal aperture (see Figs. 2
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. and 3).
C1270 − 97 (2021)
3.1.12 element, test element, n—for the purpose of this
testing, a test element is the volume of space defined by the
boundaries of two corresponding network openings, and it
represents a straight-line shortest-course path through the
detection zone.
3.1.12.1 Discussion—It is necessary to define discrete and
repeatable straight-line shortest-course test paths through the
detection zone. This can be done by using two identical
networks (grids) made of nonconductive/nonmagnetic material
attached across the entry and exit planes of the portal aperture
so the networks coincide. A test object on the end of a probe
can then be passed from one side of the portal aperture to the
othersidethroughcorrespondingopenings,whichresultsinthe
test object taking a reasonably straight-line shortest-course
path through the detection zone. If the networks are con-
structed so that they can be put in-place identically each time
they are used, then the test paths through the detection zone are
repeatable over time. On a detection sensitivity map the
corresponding networks appear as a rectangular grid with each
NOTE 1—Numbers are sensitivity setting values for a hypothetical
element of the grid representing a test path through the
detector. The numbers represent the lowest sensitivity setting at which the
detection zone.
object was detected ten out of ten consecutive test passes through the
indicated test path. 3.1.13 in-plant, adj—installed in the location, position, and
NOTE2—Itisimportanttoensurethatthelocationofthetransmitterand operating environment where the device will be used.
receiverareidentified.Ifthedetectordoesnothaveadedicatedtransmitter
3.1.14 orthogonal orientation, n—as used in this practice,
and receiver, note the side from which testing is performed relative to the
orthogonal orientation refers to alignment of the longitudinal
protected area.
FIG. 2 Example of Detection Sensitivity Map axis of a test object along the xyz axes of the Cartesian
coordinate system; x is horizontal and across the portal, y is
vertical, and z is in the direction of travel through the portal
(see Fig. 1 for handgun orientations).
3.1.15 portal, n—see walk-through metal detector.
3.1.16 test element, n—(seeFigs. 2 and 3) for the purpose of
testing, it is necessary to define discrete and repeatable
straight-line shortest-course test paths through the detection
zone. This can be done by using two identical networks (grids)
made of nonconductive/nonmagnetic material attached across
the entry and exit planes of the portal aperture so the networks
coincide.Atest object on the end of a probe can then be passed
from one side of the portal aperture to the other side through
corresponding openings, which results in the test object taking
a reasonably straight-line shortest-course path through the
detection zone. If the networks are constructed so that they can
beputin-placeidenticallyeachtimetheyareused,thenthetest
paths through the detection zone are repeatable over time.
Thus, a test element is the volume of space defined by the
boundaries of two corresponding network openings and it
represents a straight-line shortest-course path through the
detection zone.
3.1.16.1 Discussion—On a detection sensitivity map the
corresponding networks appear as a rectangular grid with each
FIG. 3 3-D View of Detection Zones and Test Grid
element of the grid representing a test path through the
detection zone.The element defining the critical test path is the
critical test element.
3.1.11.2 test path, n—as defined by an element on a detec- 3.1.17 test grid, n—a network of nonconductive/
tion sensitivity map, a straight-line shortest-course path nonmagnetic material, such as string or tape, can be stretched
through the detection zone of a detector undergoing mapping, across the entry and exit planes of the portal aperture to define
detection sensitivity, or detection sensitivity verification test- test paths through the portal aperture; the material should not
ing. (see Fig. 3) be hygroscopic.
C1270 − 97 (2021)
3.1.17.1 Discussion—See Fig. 2 for an example ofa4by9 performance testing to assure complete detection coverage
element test grid. throughout the detector aperture.
3.1.18 test object, n—metallic item meeting dimension and 4.2 This practice describes two methods for determining the
material criteria used to evaluate detection performance. values that make up the detection sensitivity map:
4.2.1 In the first, a test object, which is usually specified by
3.1.18.1 critical test object, n—theonetestobjectoutofany
requirements of the responsible regulatory authority, is passed
given group of test objects that in its critical orientation,
through the detection zone in each of the identified test paths
produces the weakest detection signal anywhere in the detec-
and the sensitivity is adjusted to determine the lowest sensi-
tion zone.
tivity setting that results in consistent detection of the test
3.1.18.2 Discussion—Depending on the particular detector,
object in each test path. These settings are the critical sensi-
some orientation sensitive test objects may have different tivity settings and are the value entered in the re
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