Reciprocity Calibration System Type 5998

Reciprocity calibration of microphones has mainly been used only in a few laboratories and at few frequencies, often only 250 Hz and 1 kHz. With the introduction of Reciprocity Calibration System Type 9699, all of this changes.

Primary calibration laboratories, calibration service centres and larger organisations with their own calibration facilities now have the opportunity to make faster and more accurate electrical transfer impedance measurements of coupled microphones. This makes multiple-frequency calibration a feasible option, since the time required per step is greatly reduced. The included measurement and calculation software is one of the benefits of using Type 9699. The software controls the system via an IEEE–488 bus, and afterwards handles the calculations. This makes the measurement task semi-automatic and greatly reduces the risk of making errors during calculation of final calibration results.

Reciprocity Calibration System Type 9699 is based on Reciprocity Calibration Apparatus Type 5998, together with a set of standard hardware components. More details about Type 5998 are found on page 5. Included with the system are two PC programs, one to control measurements and the other to handle the sensitivity calculations according to IEC 1094 – 2. A reciprocity calibration system similar to Type 9699 has been used for several years by DPLA, the Danish Primary Laboratory of Acoustics*, and has also been sold to other national laboratories.