Acoustics. Reference zero for the calibration of audiometric equipment - Reference equivalent threshold sound pressure levels for pure tones and insert earphones Ingestion-build-137917 ISO 20251 mentions that the

ISO 20251 mentions that the tests need to be performed under the standard atmosphere as mentioned

BS IEC 62531 on property specification language is useful for:

This International Standard specifies requirements and tests for systems with adaptable linear geometry for cable guiding intended for the accommodation and retention of cables and possibly other electrical equipment in electrical and/or communication systems installations

and corresponding examples of documentation

and it is particularly important where there is an entrance to an assembly building from a shopping mall that the guidance given in BS 5588-10 is followed

Acoustics. Reference zero for the calibration of audiometric equipment - Reference equivalent threshold sound pressure levels for pure tones and insert earphones Ingestion-build-137917 ISO 20251 mentions that the1 Scope This part of ISO 389 specifies reference equivalent threshold sound pressure levels (RETSPL) for the calibration of pure tone audiometers supplementary to those specified in ISO 389: 19911). Values given in this part of ISO 389 are applicable to insert earphones of a pattern specified in clause 4. NOTE 1 For information, a note on the derivation of the reference values and the origin of the data input is given in annex A, and a bibliography is