1、Designation: C 1309 97 (Reapproved 2003)Standard Practice forPerformance Evaluation of In-Plant Walk-Through MetalDetectors1This standard is issued under the fixed designation C 1309; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、 the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.INTRODUCTIONNuclear regulatory authorities require personnel entering designated security areas to be screenedfor co
3、ncealed weapons and personnel exiting areas containing specified quantities of special nuclearmaterial to be screened for metallic nuclear shielding materials. Portal-type walk-through metaldetectors are widely used to implement these requirements. This practice provides guidelines forevaluating the
4、 in-plant performance of walk-through metal detectors.1. Scope1.1 This practice is one of several (see Appendix X1)developed to assist operators of nuclear facilities with meetingthe metal detection performance requirements set by regulatoryauthorities.1.2 This practice consists of four procedures u
5、seful forevaluating the in-plant performance of walk-through metaldetectors (see Fig. 1).1.2.1 Two of the procedures provide data for evaluatingprobability of detection. These procedures use binomial data(alarm/not alarm).1.2.1.1 The detection sensitivity test (DST)2is the initialprocedure in the de
6、tection probability evaluation series. It isused to establish the probability of detection immediately afterthe detector has been adjusted to its operational sensitivitysetting.1.2.1.2 The detection sensitivity verification test (DSVT)2procedure periodically provides data for evaluation of continu-i
7、ng detection performance.1.2.2 The third procedure is a “functional test.” It is usedroutinely to verify that a metal detector is operating andresponds with the correct audio and visual signals whensubjected to a condition that should cause an alarm.1.2.3 The fourth procedure is used to verify that
8、alarmsgenerated during detection sensitivity testing were likely theresult of the detection of metal and not caused by outsideinterferences or the perturbation of the detection field by thetesters body mass.1.2.3.1 This procedure also can be used to establish aprobability of occurrence for false ala
9、rms, for example, 20 testpasses by a clean-tester resulting in no alarms indicates a falsealarm probability of less than 0.15 at 95 % confidence. Thisprocedure is optional unless required by the regulatory author-ity.1.3 This practice does not set test object specifications. Thespecifications should
10、 be issued by the regulatory authority.1.4 This practice is intended neither to set performancelevels nor to limit or constrain technologies.1.5 This practice does not address safety or operationalissues associated with the use of walk-through metal detectors.2. Referenced Documents2.1 ASTM Standard
11、s:C 1238 Guide for Installation of Walk-Through Metal De-tectors3C 1269 Practice for Adjusting the Operational SensitivitySetting of In-Plant Walk-Through Metal Detectors3C 1270 Practice for Detection Sensitivity Mapping of In-Plant Walk-Through Metal Detectors3F 1468 Practice for Evaluation of Meta
12、llic Weapons Detec-tors for Controlled Access Search and Screening43. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 clean-tester, na person who does not carry anyextraneous metallic objects that would significantly alter thesignal produced when the person carries a test object.
13、1This practice is under the jurisdiction of ASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.12 on SafeguardApplications.Current edition approved Dec. 10, 1997. Published February 1998. Originallypublished as C 1309 95. Last previous edition approved in 19
14、97 as C 1309 97.2The DST is one of two procedures used to evaluate detection rate. TheDetection Sensitivity Verification Test (DSVT) is the other. In the evaluation teststrategy, the DST is used to initially determine and document the detection rate andthen the DSVT is used to periodically check tha
15、t the detection rate continues to meetthe requirements.3Annual Book of ASTM Standards, Vol 12.01.4Annual Book of ASTM Standards, Vol 15.07.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.1.1 DiscussionBy example but not limitatio
16、n, suchextraneous metallic objects may include: metallic belt buckles,metal buttons, cardiac pacemakers, coins, metal frame eye-glasses, hearing aids, jewelry, keys, mechanical pens andpencils, shoes with metal shanks or arch supports, metallicsurgical implants, undergarment support metal, metal zip
17、pers,etc. In the absence of other criteria, a clean-tester passingthrough a metal detector shall not cause a disturbance signalgreater than 10 % of that produced when carrying the criticaltest object through the detector. Test objects requiring veryhigh sensitivity settings for detection require mor
18、e completeelimination of extraneous metal to obtain less than 10 % signaldisturbance. The tester shall have a weight between 50104 kgand a height between 1.441.93 m. Should a given detector besensitive to body size because of design or desired sensitivity,the physical size of testers should be small
19、er and within anarrower range. It is recommended that the clean-tester beNOTE 1The number of detection sensitivity verification tests in a series, the number of passes per test, the acceptance criteria, and the frequency maybe established by regulatory authority or set by the security organization b
20、ased on threat scenarios or vulnerability assessments; the numbers should besufficient to provide a degree of assurance commensurate with the detector application.NOTE 2If the detector fails to meet the acceptance criteria, the verification series is terminated. The detector then must be tested to r
21、eestablish theprobability of detection. If the probability of detection requirement cannot be met (repairs may be necessary), the detector must be mapped and theoperational sensitivity setting reestablished. Performance testing can then be resumed starting with a new detection sensitivity test.NOTE
22、3If the detector fails the functional test, the detector must be immediately removed from service (see Appendix X1).FIG. 1 Walk-Through Metal Detector Evaluation Testing ProgramC 1309 97 (2003)2surveyed with a high sensitivity hand-held metal detector toensure that no metal is present.3.1.2 critical
23、 orientation, nthe orthogonal orientation of atest object that produces the smallest detection signal orweakest detection anywhere in the detection zone; the orthogo-nal orientation of a test object that requires a higher sensitivitysetting to be detected compared to the sensitivity settingsrequired
24、 to detect the object in all other orthogonal orienta-tions. See Fig. 2 for handgun orientations.3.1.2.1 DiscussionCritical orientations are determined bytesting using a mapping procedure such as described inPractice C 1270 (see 3.1.21 and Fig. 3).3.1.2.2 DiscussionThe term critical orientation can
25、beapplied in two ways. Critical orientation can refer to the worstcase orthogonal orientation in a single test path or the worstcase orthogonal orientation for all the test paths (the entiredetection zone). The two are coincident in the critical test path.3.1.3 critical sensitivity setting, nthe low
26、est sensitivitysetting of a detector at which the critical test object in itscritical orientation is consistently detected (10 alarms out of 10passages) when passed through the detection zone on thecritical test path.3.1.4 critical test element, nsee test element.3.1.5 critical test object, nthe one
27、 test object out of anygiven group of test objects that, in its critical orientation,produces the weakest detection signal anywhere in the detec-tion zone.3.1.5.1 DiscussionThe group referred to consists of oneor more objects that are to be detected at the same detectorsetting.3.1.5.2 DiscussionDepe
28、nding on the particular detector,some orientation-sensitive test objects may have differentcritical orientations through different test paths in the detectionzone. Hence, care must be taken in determining the critical testobject, its critical orientation, and the critical test path.3.1.6 critical te
29、st path, nthe straight-line shortest-coursepath through the portal aperture, as defined by an element onthe detection sensitivity map, that produces the smallestdetection signal or weakest detection for a test object in itscritical orientation (see Fig. 4 and Fig. 2).3.1.7 detection sensitivity map
30、(see Fig. 3 and AppendixX2), na depiction of the grid used to define test pathsthrough the detection zone, with each element of the gridcontaining a value, usually the sensitivity setting of thedetector, that is indicative of the detectability of the test object.3.1.7.1 DiscussionThese values are re
31、lative and describethe detection sensitivity pattern within the detection zone forthe specific test object. The values are derived by identicallytesting each defined test path using a specific test object in asingle orthogonal orientation. The value is usually the mini-mum sensitivity setting of the
32、 detector that will cause aconsistent alarm (10 out of 10 test passes when the test objectFIG. 2 Six Standard Orthogonal Orientations for a HandgunNOTE 1Numbers are sensitivity setting values for a hypotheticaldetector. The numbers represent the lowest sensitivity setting at which theobject was dete
33、cted ten out of ten consecutive test passes through theindicated test path.FIG. 3 Example of Detection Sensitivity MapFIG. 4 3-D View of Detection Zones and Test GridC 1309 97 (2003)3is passed through the detection field. Appendix X2 is a sampleform for a potential detection sensitivity map configur
34、ation.)3.1.8 detection sensitivity test, nsee 6.2.3.1.9 detection sensitivity verification test, nsee 6.3.3.1.10 detection zone, nthe volume within the portalaperture.3.1.11 detector, nsee walk-through metal detector.3.1.12 element, nsee test element.3.1.13 event false alarm, nan alarm occurring whe
35、n aclean-tester, while not carrying a test object, passes through thedetection zone of a detector operating at the operationalsensitivity setting.3.1.14 event false alarm test, nsee 6.4.3.1.15 functional test, nsee 6.1.3.1.16 functional test object, na metallic item that doesnot necessarily have str
36、ict criteria defining its size, form,weight, or composition.3.1.16.1 DiscussionFunctional test objects do not testsensitivity; they are gross stimuli used frequently to quicklyverify that the aural and visual indicators and alarm circuits areoperable.3.1.16.2 DiscussionA functional test object will
37、consis-tently cause metal detection alarms when a detector is adjustedto detect the critical test object in its critical orientation passingthrough the critical test path. Detection of the functional testobject does not provide assurance that the detector is operatingproperly or adjusted to detect a
38、nything other than the func-tional test object.3.1.16.3 DiscussionFunctional test objects may be itemssuch as large handguns or rifles, metal tools, metal blocks, aperson wearing many metallic items, etc. Active devices suchas radios and pagers must not be used as functional test objectsand must not
39、 be carried when performing tests. The functionaltest object must be at least as detectable as the critical testobject in its critical orientation.3.1.17 grid, nsee test grid3.1.18 grid element, n(1) a single block on a detectionsensitivity map; (2) the rectilinear volume through the detec-tion zone
40、 defined by coincident elements of identical gridworks placed on either side of the portal aperture. (See Figs. 3and 4)3.1.18.1 DiscussionGrid elements define the bounds ofrepeatable straight-line shortest-course paths through the de-tection zone (see Fig. 4).3.1.19 in-plant, adjinstalled in the loc
41、ation, position, andoperating environment where the device will be routinely used.3.1.20 normal screening method, nthe usual method ofpassage through a walk-through metal detector during normaloperations. For example, the two basic screening methods are“continuous walk” and “pausing in the portal.”3
42、.1.20.1 DiscussionThe normal screening method is usu-ally based on the operating characteristics of the detector. Abasic rule for metal detector testing is:“ Use it like you test itand test it like you use it.”3.1.21 orthogonal orientation, nas used in this practice,orthogonal orientation refers to
43、alignment of the longitudinal(long) axis of a test object along the XYZ axes of the Cartesiancoordinate system; X is horizontal and across the portal; Y isvertical; and Z is in the direction of travel through the portal.(See Fig. 2 for handgun orientations)3.1.21.1 In the case of firearms, the barre
44、l is always treatedas the longitudinal axis. Fig. 2 illustrates the six standardorthogonal orientations for a handgun.3.1.22 performance test log, na record of the operation,testing, and maintenance history of a metal detector.3.1.22.1 DiscussionAppendix X4, Performance Test Log,suggests examples fo
45、r log content and format.3.1.23 portal, nsee walk-through metal detector.3.1.24 shielding test object, na test object representingspecial nuclear material shielding that might be used in a theftscenario.3.1.24.1 DiscussionIt is usually a metallic container ormetallic material configured as a credibl
46、e gamma radiationshield for a specific type and quantity of special nuclearmaterial. The object is specified by a regulatory authority or isbased on the facility threat/risk assessment, or both3.1.25 test element, n(see Fig. 1) for the purpose oftesting, it is necessary to define discrete and repeat
47、ablestraight-line shortest-course test paths through the detectionzone. This can be done by using two identical networks (grids)made of nonconductive/nonmagnetic material attached acrossthe entry and exit planes of the portal aperture so the networkscoincide. A test object on the end of a probe can
48、then be passedfrom one side of the portal aperture to the other side throughcorresponding openings, which results in the test object takinga reasonably straight-line shortest-course path through thedetection zone. If the networks are constructed so that they canbe put in-place identically each time
49、they are used, then the testpaths through the detection zone are repeatable over time.Thus, a test element is the volume of space defined by theboundaries of two corresponding network openings and itrepresents a straight-line shortest-course path through thedetection zone.3.1.25.1 DiscussionOn a detection sensitivity map thecorresponding networks appear as a rectangular grid with eachelement of the grid representing a test path through thedetection zone. The element defining the critical test path is thecritical test element.3.1.26 test
