Sound Level Meters are electrically tested using the synthesizer and the reference voltmeter for: full scale attenuator, self noise, primary range linearity, weighting filters, RMS time constants, peak detector, averaging, overload detector.
The microphone test can be performed using an acoustic coupler where two microphones are mounted face to face, one of them being the reference, or alternatively with an electrostatic actuator providing special insulated microphone grids to be fitted on the microphone under test.
In the Filter section there is a test of filter shape on 17 points and the filter response time according to IEC 1260.
Calibrators are tested for exact level produced using an “Insert Voltage” preamplifier connected to the SCS 5013A front-end unit, exact frequency generated and THD can be measured with an FFT analyzer.
The software interface guides the operator through all the tests and for preparation of results files which are automatically read by Microsoft Word (MACRO) to prepare a test report. Results data are stored in an internal data base in Microsoft Access.