CPDM Certified Person Sampling Test No. 4 Taken from the CPDM Certified Person Sampling Exam Pool Progress Indicator: Question 1 of 25 1.  MSHA may revoke a person’s certification to conduct respirable coal mine dust sampling with a CPDM for _________. Choices: failure to properly carry out the required sampling procedures checking the CPDM at mid shift during sampling training the miner being sampled on how to start and stop a short term sample run during compliance sampling none of the above