Posted By Peter Vintner Hello Safety Profs. Can anyone tell me if it necessary to have both an audiometer and calibrator calibrated. I have a dual calibrator (94 and 104dBA) and feel that this if regularly calibrated to the standards set by the National Physical Laboratory it should be adequate to calibrate the audiometer. Any differences of opinion or further information would be welcomed. Pete

Posted By Paul Maddock Peter, Although calibrating your audiometer from a calibrated calibrator/pistophone is not a bad idea, please bear in mind that the calibrator only sends the test signal at 1000Hz. It may therefore be the case that your audiometer is fine at this frequency but may have drifted at others. It is typically recommended that sound measurement equipment be periodically tested by a competent body every 2-years, but if cost is an issue (it is not cheap to do this), then the use of the calibrated pistophone is fine, as long as you remember its limitations. Regards, Paul Maddock.