We purchased a metal detector a little less than a year ago and we have our SQF version 8 audit coming up right around the corner (in <3 weeks). We're located in Southern California but we're having a really hard time finding a third-party validation/calibration service to come out here and calibrate our detector without breaking the bank on this (and as we all know, preparing for and getting SQF audited is already a substantial financial burden/investment). So, on that note:
1) Does anyone happen to know of an affordable Southern CA service company that provides calibration services for metal detectors?
2) Our metal detector did also come with these three translucent block things, which looks like they're meant to be used to test the metal detectors (pictured below). Can these be used to test/validate our equipment by ourselves (i.e. in house)?