TYPE 9699

Microphone Primary Calibration System

Designed for calibration of laboratory standard microphones.


A primary level microphone calibration system for calibration of laboratory standard microphones. The system, Type 9699, applies the pressure reciprocity calibration technique and calibrates to the highest possible accuracy. A free-field system is available as Type 9799.

Type 9699 performs pressure reciprocity calibration according to the method described in IEC 61094-2 to determine the pressure sensitivity of microphones described in IEC 61094-1 (Laboratory Standard Microphones). The system is intended for National Metrology Institutes and other high-level laboratories. It is a turnkey system for routine measurements, which can be set up to meet the requirements of the user. The system can work in a ‘normal’ laboratory environment with no specific precautions with respect to background noise and vibration.


  • Primary open-circuit pressure sensitivity calibration of laboratory standard microphones
  • Measurements according to IEC 61094-2 on IEC 61094-1 microphone types:
    • LS1P (for example, Type 4160)
    • LS2aP (for example, Type 4180)
  • Measurement of static pressure coefficient using integral pressure chamber


  • Fast PC-controlled determination of electrical transfer impedance
  • Measurement and calibration data stored on disk or printed as hard copy
  • Frequency range: 20Hz to 10kHz (LS1), 20Hz to 20kHz (LS2)
  • Unique vibration and ambient noise damped microphone mounting stand
  • Dimensionally stable plane-wave sapphire couplers