A functional or biological check before each day of use - you do this, not us. An acoustic calibration annually, verifying output levels, frequencies, linearity and crosstalk against the standard. An exhaustive calibration every two years,…
A functional or biological check before each day of use - you do this, not us. An acoustic calibration annually, verifying output levels, frequencies, linearity and crosstalk against the standard. An exhaustive calibration every two years, covering the full specification. Skipping the daily check is the most common gap, and it is the one that catches a fault while it is still one day of tests rather than a year of them.
Output sound pressure level at each frequency against the reference equivalent threshold, frequency accuracy, harmonic distortion, attenuator linearity across the range, crosstalk between channels, and rise and fall times of the tone. Earphone cushions are checked and replaced when hardened - a cushion that has gone stiff changes the acoustic seal and quietly shifts every threshold you record.
If an instrument is found outside tolerance we report the as-found readings before adjustment, not just the corrected as-left figures. That matters: as-found data is what lets you judge whether audiograms taken since the last calibration are still usable, or whether a cohort needs retesting. A certificate showing only as-left values withholds exactly the information you need.
Instrument make, model and serial number. Date. Standard applied. As-found and as-left data. Traceability to national standards through the reference equipment used, with its own calibration status. Next due date. Anything less is a sticker, not a certificate.
Primary regulations and standards referenced above. Where a standard is published commercially it is named in full rather than linked to a copy.