Section 146(6) in The Coal Mines Regulations, 2011
(6)Samples shall be taken by a person who has been specially trained for the purpose in the sampling equipment and accessories that have been checked to ensure correct maintenance and efficient operation thereof and examined, treated and calibrated on a date which is not earlier than one year:Provided that if the dust sampling is carried out by a laboratory other than belonging to the mine, such laboratory shall be approved in writing by the Chief Inspector in this behalf.
