IFA calibration body for soundlevel meters used by the social accident insurance institutions

Assuring quality in sound measurement at workplaces requires regular testing of the sound-level meters. If the devices are used in the fields of occupational or environmental protection for the purpose of carrying out public monitoring responsibilities, then the devices must be authorised and officially calibrated (§ 2 paragraph 1 of the law on weights and measures [Eichgesetz] in conjunction with § 3 paragraph 1 of the weights and measures regulation [Eichordnung]).

IFA, in cooperation with the Dortmund board of weights and measures [Eichamt Dortmund], provides the institutions for statutory accident insurance and prevention with the opportunity to have their soundlevel meters officially calibrated. The Cologne-based directorship for the boards of weights and measures [Eichdirektion Köln] recognises IFA as a calibration body. For soundlevel meters that are not subject to the board of weights and measures, IFA offers individual tests that are identical to the official calibration in terms of the scope of the tests and the given error tolerance. The basis of the tests are the respective soundlevel meter standards, such as DIN EN 60651, DIN EN 60804, and DIN IEC 61672.

In the framework of the official calibration or the individual IFA test at intervals of every two years, those specifications are inspected that can change over a period of use or that have a particularly high exemplary dispersion. The tests include the following:

• Test of the transfer factor and the frequency response in a free field (see Figure)
• Test of the frequency weighting curves
• Test of the rectification
• Test of the overall dynamic properties (time weighting)
• Test of the level linearity
• Test of the level integration