ASTM C1270-97(2012)

Standard Practice for Detection Sensitivity Mapping of In-Plant Walk-Through<brk> Metal Detectors

SIGNIFICANCE AND USE
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.
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.
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 support of performa...
SCOPE
1.1 This standard 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.

General Information

• Status: Historical
• Publication Date: 31-Dec-2011
• ICS: 03.080.30 - Services for consumers
• ICS: 13.320 - Alarm and warning systems
• Technical Committee: C26 - Nuclear Fuel Cycle

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: C1270 − 97 (Reapproved 2012)
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 and
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.
1. Scope 1.2 This practice is one of several developed to assist
operators of walk-through metal detectors with meeting the
1.1 This standard practice covers a procedure for determin-
metal detection performance requirements of the responsible
ing the weakest detection path through the portal aperture and
regulatory authority. (See Appendix X2)
the worst-case orthogonal orientation of metallic test objects. It
resultsindetectionsensitivitymaps,whichmodelthedetection 1.3 This practice is neither intended to set performance
zone in terms related to detection sensitivity and identify the levels, nor limit or constrain operational technologies.
weakest detection paths. Detection sensitivity maps support
1.4 This practice does not address safety or operational
sensitivity adjustment and performance evaluation procedures
issues associated with the use of walk-through metal detectors.
(see Practices C1269 and C1309).
1.5 The values stated in SI units are to be regarded as the
NOTE 1—Unsymmetrical metal objects possessing a primary longitu-
standard. The values given in parentheses are for information
dinal component, such as handguns and knives, usually have one
only.
particular orientation that produces the weakest detection signal. The
orientation and the path through the detector aperture where the weakest
2. Referenced Documents
response is produced may not be the same for all test objects, even those
with very similar appearance.
2.1 ASTM Standards:
NOTE 2—In the case of multiple specified test objects or for test objects
C1238 Guide for Installation of Walk-Through Metal Detec-
that are orientation sensitive, it may be necessary to map each object
several times to determine the worst-case test object or orientation, or tors
both.
C1269 Practice for Adjusting the Operational Sensitivity
Setting of In-Plant Walk-Through Metal Detectors
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 Jan. 1, 2012. Published January 2012. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1994. Last previous edition approved in 1997 as C1270 – 97(2003). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/C1270-97R12. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1270 − 97 (2012)
C1309 Practice for Performance Evaluation of In-Plant 3.1.2.2 Discussion—The term critical orientation can refer
Walk-Through Metal Detectors to the worst case orthogonal orientation in a single test path or
F1468 Practice for Evaluation of Metallic Weapons Detec- the worst case orthogonal orientation for all the test paths (the
tors for Controlled Access Search and Screening entiredetectionzone).Thetwoarecoincidentinthecriticaltest
path.
3. Terminology
3.1.3 critical sensitivity setting, n—the lowest sensitivity
3.1 Definitions of Terms Specific to This Standard:
setting of a detector at which the critical test object in its
3.1.1 clean-tester, n—a person who does not carry any
critical orientation is consistently detected (10 out of 10 test
extraneous metallic objects that would significantly alter the
passes) when passed through the detection zone on the critical
signal produced when the person carries a test object.
test path.
3.1.1.1 Discussion—By example but not limitation, such
3.1.4 critical test element, n—see test element.
extraneous metallic objects may include: metallic belt buckles,
3.1.5 critical test object, n—see test object.
metal buttons, cardiac pacemakers, coins, metal frame eye
glasses, hearing aids, jewelry, keys, mechanical pens and 3.1.6 critical test path, n—the straight-line shortest-course
path through the portal aperture, as defined by an element on
pencils, shoes with metal shanks or arch supports, metallic
surgical implants, undergarment support metal, metal zippers, the detection sensitivity map, that produces the smallest
detection signal or weakest detection for a test object in its
etc. In the absence of other criteria, a clean tester passing
through a metal detector shall not cause a disturbance signal critical orientation. (see Figs. 2 and 3)
greater than 10 % of that produced when carrying the critical
3.1.7 detection sensitivity map, n—(see Figs. 2 and 1)a
test object through the detector. Test objects requiring very
depiction of the grid used to define test paths through the
high sensitivity settings for detection require more complete
detection zone, with each element of the grid containing a
elimination of extraneous metal to obtain less than 10 % signal
value, usually the sensitivity setting of the detector, that is
disturbance.
indicative of the detectability of the test object.
3.1.1.2 Discussion—The tester shall have a weight between
3.1.7.1 Discussion—These values are relative and describe
50 to 104 kg (110 to 230 lb) and a height between 1.44 to 1.93
the detection sensitivity pattern within the detection zone for
m (57 to 75 in.). Should a given detector be sensitive to body
the specific test object. The values are derived by identically
size because of design or desired sensitivity, the physical size
testing each defined test path using a specific test object in a
of testers should be smaller and within a narrower range.
single orthogonal orientation. The value is usually the mini-
3.1.1.3 Discussion—It is recommended that the clean tester
mum sensitivity setting of the detector that will cause a
be surveyed with a high sensitivity hand-held metal detector to
consistent alarm (10 out of 10 test passes) when the test object
ensure that no metal is present.
3.1.2 critical orientation, n—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 setting
required to detect the object in all other orthogonal orienta-
tions. See Fig. 1 for handgun orientations.
3.1.2.1 Discussion—Critical orientations are determined by
testing using a mapping procedure such as described in
Practice C1270.
NOTE 1—Numbers are sensitivity setting values for a hypothetical
detector. The numbers represent the lowest sensitivity setting at which the
object was detected ten out of ten consecutive test passes through the
indicated test path.
NOTE 2—Important: ensure that the location of the transmitter and
receiverareidentified.Ifthedetectordoesnothaveadedicatedtransmitter
and receiver, note the side from which testing is performed relative to the
protected area.
FIG. 1 Six Standard Orthogonal Orientations for a Handgun FIG. 2 Example of Detection Sensitivity Map
C1270 − 97 (2012)
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
element of the grid representing a test path through the
detection zone.
3.1.13 in-plant, adj—installed in the location, position, and
operating environment where the device will be used.
3.1.14 orthogonal orientation, n—as used in this practice,
orthogonal orientation refers to alignment of the longitudinal
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
FIG. 3 3-D View of Detection Zones and Test Grid 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
is passed through the detection field. Appendix X3 is a sample
detection zone. If the networks are constructed so that they can
form for a potential detection sensitivity map configuration.
beputin-placeidenticallyeachtimetheyareused,thenthetest
3.1.8 detection zone, n—the volume within the portal aper-
paths through the detection zone are repeatable over time.
ture.
Thus, a test element is the volume of space defined by the
3.1.9 detector, n—see walk-through metal detector.
boundaries of two corresponding network openings and it
3.1.10 element, n—see test element
represents a straight-line shortest-course path through the
detection zone.
3.1.11 grid, n—see test grid
3.1.16.1 Discussion—On a detection sensitivity map the
3.1.11.1 grid element, n—(1) a single block on a detection
corresponding networks appear as a rectangular grid with each
sensitivity map; (2) the rectilinear volume through the detec-
element of the grid representing a test path through the
tion zone defined by coincident elements of identical grid
detection zone.The element defining the critical test path is the
works placed on either side of the portal aperture. (see Figs. 2
critical test element.
and 3)
3.1.17 test grid, n—a network of nonconductive/
3.1.11.2 test path, n—as defined by an element on a detec-
nonmagnetic material, such as string or tape, can be stretched
tion sensitivity map, a straight-line shortest-course path
across the entry and exit planes of the portal aperture to define
through the detection zone of a detector undergoing mapping,
test paths through the portal aperture; the material should not
detection sensitivity, or detection sensitivity verification test-
be hygroscopic.
ing. (see Fig. 3)
3.1.17.1 Discussion—See Fig. 2 for an example ofa4by9
3.1.12 element, test element, n—for the purpose of this
element test grid.
testing, a test element is the volume of space defined by the
3.1.18 test object, n—metallic item meeting dimension and
boundaries of two corresponding network openings, and it
material criteria used to evaluate detection performance.
represents a straight-line shortest-course path through the
3.1.18.1 critical test object—the one test object out of any
detection zone.
given group of test objects that in its critical orientation,
3.1.12.1 Discussion—It is necessary to define discrete and
produces the weakest detection signal anywhere in the detec-
repeatable straight-line shortest-course test paths through the
tion zone.
detection zone. This can be done by using two identical
networks (grids) made of nonconductive/nonmagnetic material 3.1.18.2 Discussion—Depending on the particular detector,
attached across the entry and exit planes of the portal aperture some orientation sensitive test objects may have different
so the networks coincide. A test object on the end of a probe locations in the detection zone result in near critical sensitivity
can then be passed from one side of the portal aperture to the settings. Hence, care must be taken in determining the critical
othersidethroughcorrespondingopenings,whichresultsinthe test object, its critical orientation, and the critical test path.
test object taking a reasonably straight-line shortest-course 3.1.18.3 shielding test object, n—a test object representing
path through the detection zone. If the networks are con- special nuclear material shielding that might be used in a theft
structed so that they can be put in-place identically each time scenario.
C1270 − 97 (2012)
3.1.18.4 Discussion—It is usually a metallic container or than full scale readings for the most sensitive path through the
metallic material configured as a credible gamma-radiation detection zone). These mean values describe the sensitivity
shield for a specific type and quantity of special nuclear pattern.
material. The object is specified by a regulatory authority or is
4.3 Testobjectsthatareorientationsensitivemusthaveeach
based on the facility threat analysis, or both.
orthogonal orientation tested to determine the worst-case
3.1.18.5 weapon test object, n—a handgun(s) or simulated
orientation.
handgun designated by or satisfying the regulatory authority
requirement for a test object. 5. Significance and Use
5.1 A complex set of variables affect metal detection and
3.1.18.6 Discussion—Care must
...