The Diesel Smoke Meter (DSM) specification for opacity meters has been amended. The new revision is V5.4 Dated July 2023, replacing V5.3 April 23.The changes to the specification is correcting and error that was published in V5.3 for LEV testing (Page 7)  on the number of tests to be performed and removing the reference to RPC testing.This revision also has some minor grammar/ formatting corrections.The full specification document can be accessed from the GEA website, technical library, DVSA – equipment specifications DVSA – Equipment Specifications – GEA – Garage Equipment Association