Calibration of micrometer calipers and digital calipers

A.Calibration checks are performed annually on all in-service micrometer calipers and digital calipers in the Trace Evidence
Section.
a.Calibration checks are made with the following five certified steel standard gauge blocks:0.150�?0.250�?
0.500�?0.750”and 1.000�?
b.The measured values are recorded on a log sheet(Appendix 19)which is stored with the micrometer calipers and
digital calipers.
c.The measured values shall be within:±0.001�?
d.If the values are outside the appropriate range for a given steel block,then measure again.If the values are still
outside the appropriate range,then the micrometer caliper or digital caliper must be sent to an outside vendor for
recalibration.
e.If the digital caliper comes with a calibration due date and it continues to perform within an acceptable range,
then it is not necessary to return the digital caliper to an outside vendor for recalibration.
f.If any micrometer caliper or digital caliper is dropped or otherwise subjected to extremes of temperature,shock
or contamination,then the calibration will be checked in accordance with? A.a.prior to use in casework measurements.