1、Designation: D7013/D7013M 15Standard Guide forCalibration Facility Setup for Nuclear Surface Gauges1This standard is issued under the fixed designation D7013/D7013M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This guide outlines procedures for setup of a nucleargauge calibration facility in either a shielded bay or anunshielded a
3、reaGuide A and Guide B, respectively.1.2 This guide does not attempt to describe the calibrationtechniques or methods. It is assumed that this guide will beused by persons familiar with the operations of the gauge andin performing proper calibration, service and maintenance.1.3 This guide does not a
4、ttempt to address maintenance orservice procedures related to the gauge.1.4 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other.
5、 Combiningvalues from the two systems may result in non-conformancewith the standard.1.5 This guide does not purport to address all of the safetyconcerns, if any, associated with its use. It is the responsibilityof the user of this guide to establish appropriate safety, andhealth practices and deter
6、mine the applicability of regulatorylimitations prior to use.1.6 This guide offers an organized collection of informationor a series of options and does not recommend a specificcourse of action. This document cannot replace education orexperience and should be used in conjunction with professionalju
7、dgment. Not all aspects of this guide may be applicable in allcircumstances. This ASTM standard is not intended to repre-sent or replace the standard of care by which the adequacy ofa given professional service must be judged, nor should thisdocument be applied without consideration of a projects ma
8、nyunique aspects. The word “Standard” in the title of thisdocument has been approved through ASTM consensus pro-cess.1.7 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inpractice D6026.1.7.1 The method used to specify how data are co
9、llected,calculated, or recorded in this standard is not directly relatedto the accuracy to which the data can be applied in the designor other uses, or both. How one applies the results obtainedusing this standard is beyond its scope.2. Referenced Documents2.1 ASTM Standards:2D653 Terminology Relati
10、ng to Soil, Rock, and ContainedFluidsD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD6026 Practice for Using Significant Digits in GeotechnicalDataD6938 Test Method for In-Place Density and Water
11、Contentof Soil and Soil-Aggregate by Nuclear Methods (ShallowDepth)3. Terminology3.1 For definitions of common technical terms in thisstandard, refer to Terminology D653.3.2 Definitions of Terms Specific to This Standard:3.2.1 cinder blocka hollow building block made withconcrete and coal cinders.3.
12、2.2 high density concrete blockssolid concrete blocksdesigned for areas requiring radiation shielding.3.2.3 safe positionposition of the density source duringthe standardization process of the gauge.3.2.4 shielded calibration bayan enclosed area sur-rounded by walls in order to reduce background rad
13、iation to anacceptable level.3.2.5 shielded storage bayan enclosed area with sufficientshielding material to maintain and control radiation back-ground in the facility and to reduce influences from storedgauges.1This guide is under the jurisdiction ofASTM Committee D18 on Soil and Rockand is the dir
14、ect responsibility of Subcommittee D18.08 on Special and Construc-tion Control Tests.Current edition approved May 1, 2015. Published June 2015. Originallyapproved in 2004. Last previous edition approved in 2011 as D701311. DOI:10.1520/D7013_D7013M-15.2For referenced ASTM standards, visit the ASTM we
15、bsite, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor
16、 Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.6 unshielded areaan open area within a calibrationfacility where the closest wall is a minimum of1m3ftfromthe spot in which the gauge is being calibrated.4. Summary of Method4.1 Nuclear moisture density gauges require proper ca
17、libra-tion. Since these gauges contain radioactive isotopes, influ-ences from the surroundings and other gauges should becontrolled during the calibration process. This guide providesprocedures to facilities involved in calibration of one or moregauges in a shielded bay or and an unshielded area. Th
18、e goal ofthis guide is to provide a calibration and storage facility forproper gauge calibration.5. Significance and Use5.1 To establish a proper calibration area for nuclear surfacegauges.5.2 To reduce the chance of improper calibration.NOTE 1The quality of the results produced by this standard isd
19、ependent on the competence of the personnel performing it, and thesuitability of the equipment and facilities used. Agencies that meet thecriteria of practice D3740 are generally considered capable of competentand objective testing/inspection/etc. Users of this standard are cautionedthat compliance
20、with practice D3740 does not in itself assure a means ofevaluating some of those factors.6. Apparatus6.1 Calibration reference block(s) as per the requirements ofTest Method D6938 with density certification from a qualifiedcalibration facility.6.2 High density concrete blocks 9 cm high 20 cm wide 41
21、 cm long 3.5 in. 8 in. 16 in. or cinder blocks 20 cm high 20 cm wide 41 cm long 8 in. 8 in. 16 in. filled withsand or other fine aggregate materials for construction of baywalls.6.3 Lead sheet 1 to 6 mm 0.032 to 0.25 in. thick for liningthe bay walls. The exposed surfaces containing lead should bepa
22、inted or covered.6.4 Miscellaneous hardware for securing lead sheets to thecalibration bay walls.7. Shielded Storage Bay Setup7.1 Set up a shielded storage bay if more than five gaugesare routinely stored at a distance of 10 m 33 ft or less fromthe area where gauge calibration is to take place. If f
23、ive or lessgauges are routinely stored in the storage area, concrete wallsare not necessary. However, gauges should be stored in theirshipping cases or likewise secured while other gauges arebeing calibrated. Refer to Appendix X1 for examples ofshielded storage bay configurations.7.1.1 The storage b
24、ay should not be set up directly under orover the area where gauges are to be calibrated.7.1.2 Stagger the blocks during wall construction to reducegaps between blocks and to improve wall integrity.7.1.3 If more than five gauges are routinely stored in thestorage bay, build a wall made from high den
25、sity concrete orcinder blocks filled with sand or fine aggregate material.7.1.4 The wall thickness for the storage bay should be aminimum of 410 mm 16 in. The wall should completelysurround the area where the gauges are planned to be stored. Ifgauges are stored on shelves that are elevated from the
26、floor,the height of the wall should be a minimum of 0.5 m 20 inabove the height of the shelves on which gauges are stored.NOTE 2Additional requirements might be necessary in order to meetstate and federal licensing regulations. These requirements might include,lockable doors to limit access and appr
27、opriate caution signs. Users shouldcheck their materials license requirements and check with their regulatoryagency when building storage bays for nuclear gauges.8. Guide A: Shielded Calibration Bay Setup8.1 Set up a shielded calibration bay if two or more gaugesare going to be calibrated simultaneo
28、usly, and the spacebetween gauges being calibrated is less than 10 m 33 ft. If thegauge in storage bay is less than 10 m 33 ft from the areawhere the calibration is going to take place, or if the area wheregauges are routinely serviced is less than 10 meters 33 ft fromthe calibration area. Refer to
29、Appendix X1 for examples ofshielded calibration bay configurations.NOTE 3Use Guide B if 8.1 does not apply to your calibration facility.8.1.1 Determine the number of bays required for calibrationof nuclear gauges. This can be based on the number of gaugescalibrated per year and can vary from one to
30、several bays.8.1.2 The bay inside dimensions should be establishedbased on the bay walls being a minimum of 610 mm 24 in.from the center of calibration blocks and lined with 1 mm0.032 in. of lead. Smaller inside dimensions can be used iflead sheets thicker than 6 mm 0.25 in. are used on the walls.Ho
31、wever, under no circumstances should the walls be less than610 mm 24 in. from center of the calibration block.NOTE 4Lead sheets may not be required, if it is determined that thewall influence (counts inside and outside the bay (See 8.2.1) is within anacceptable limit.8.1.3 The calibration bay wall t
32、hickness should be a mini-mum of 410 mm 16 in. thick.The walls should be constructedusing high-density concrete blocks or cinder blocks filled withsand or fine aggregate material. Stagger the blocks during wallconstruction to reduce gaps between blocks and to improvewall integrity.8.1.4 The wall hei
33、ght should be at a minimum from 1.0 to1.3 m 40 to 50 in.8.1.5 Design and construct the bay such that the opening ofthe bay is not in direct line with the opening of the storage bayor the area where the gauges are serviced.8.1.6 Center the calibration reference block(s) in the bay.8.2 Wall Influence
34、VerificationThe response to the sur-rounding walls can vary significantly for different gaugegeometries. For accurate calibration, influence from the wallsshould be eliminated.8.2.1 Place a gauge on a calibration reference block.8.2.2 Take two four minute measurements, in Backscatterand 300 mm 12 in
35、. position, and take a four minutemeasurement at each source rod increment of 50 mm 2 in.,between depth 50 mm 2 in. and depth 250 mm 10 in. Foreach of these measurements, record the density count forevaluation. If the calibration reference block is a high moisturereference block, then and only then,
36、 for each measurement,record the moisture counts for evaluation.D7013/D7013M 1528.2.3 Repeat step 8.2.2 for each calibration reference blockin the bay.8.2.4 Move the calibration reference block(s) out of the bay,a minimum of 1 m 3 ft from any walls and 10 meter 33 ftfrom other gauges.8.2.5 Repeat st
37、eps 8.2.1 through 8.2.4 with the same gauge.8.2.6 For each source rod position, the difference betweenthe counts in steps 8.2.2 and 8.2.5 should be less than 61.0 %.Determine the difference by equation Eq 1 and record to 0.1 %Difference 5SLarger Count 2 Smaller CountLarger CountD3100 (1)8.2.7 If the
38、 difference in the counts are higher than the 61.0 % limit, increase the inside wall dimensions or the leadliner thickness and repeat the steps in 8.2.1 8.2.6.8.2.8 Repeat this procedure for all model gauges that arecalibrated in your facility.8.3 Reference Standard Count VerificationThe size andgeo
39、metry of gauges will have an effect on the accuracy of thestandard counts. For accurate calibration, standard counts takenon top of calibration reference block(s) should closely matchcounts taken on the ground.8.3.1 Place the gauge on its reference standard block on topof the calibration reference b
40、lock which is to be used for gaugestandardization.8.3.2 Take a 20 minute standardization count. For example,average of 20 one minute counts, average of 5 four minutecounts, etc.8.3.3 Record the moisture and density count.8.3.4 Remove the calibration reference block from thecalibration bay.8.3.5 Plac
41、e the gauge on the reference standard block in safeposition in the middle of the bay on the floor.8.3.6 Take a total of 20 min standardization count.8.3.7 Record the moisture and density counts.8.3.8 Compare the counts in step 8.3.3 8.3.7. The differ-ence in counts as calculated by equation 1 should
42、 be less thanor equal to 6 2.0 % for moisture standard and 6 1.0 % fordensity standard.8.3.9 If the differences exceed the limits given in 8.3.8,expand the bay dimensions, apply correction factors for thecounts taken on top of the calibration reference block(s) or takethe standard counts on the grou
43、nd. 8.3 should be repeated foreach gauge model calibrated in your facility.8.4 Between Bay Cross Talk VerificationSufficient shield-ing or distance should be provided between adjacent calibra-tion bays in order to eliminate influence between bays. Eachbay should be set up to eliminate influence from
44、 gauges beingcalibrated in adjacent bays.8.4.1 Place one gauge in each bay. Place the gauges on theirreference standard block in the safe position on top of thecalibration block(s).8.4.2 Take a total of 20 minute count with each gauge ineach bay.8.4.3 Record the counts for both moisture and density
45、forboth gauges.8.4.4 Remove one of the gauges from the bay and place it inthe storage bay.8.4.5 With the second gauge still remaining in the calibra-tion bay and without moving the gauge, take a second 20minute standard count.8.4.6 Record the moisture and density counts.8.4.7 Compare the average of
46、the 20-min counts in step8.4.6 to counts for the same gauge in step 8.4.3.8.4.8 The difference in the counts in step 8.4.7 should beless than or equal to 6 1.0 % for density and 62.0 % formoisture.8.4.9 If this difference is larger than the limits in 8.4.8,increase the wall thickness between the bay
47、s or add to thethickness of the lead sheet liners attached to the wall.8.4.10 Repeat the steps in this section for each set ofadjacent bays to verify that cross talk between bays has beeneliminated.8.4.11 Repeat this section for each gauge model calibratedin the facility.NOTE 5Do not use the calibra
48、tion bays as gauge storage bays. Thismay cause inaccuracy in calibration counts taken in adjacent bays.8.5 Follow block manufacturers procedures to complete thegauge calibration.9. Guide B: Calibration in an Unshielded Area9.1 The area where the gauges are stored and are beingworked on should be at
49、least 10 m 33 ft away from the areawhere the calibration reference block(s) are placed for calibra-tion.9.2 If more than 5 gauges are kept in the facility, eitherremove the extra gauges and place 10 m 33 ft away whilecalibrating the gauges or build a shielded storage bay accordingto Section 7.9.3 If more than one gauge is being calibratedsimultaneously, place the calibration reference block(s) aminimum of 10 m 33 ft away from each other.9.4 Follow block manufacturers procedures to complete thegaug
