Low Frequency Calibration System

A microphone calibration system for determining the low-frequency frequency response of measurement microphones and other types of microphone. The system, Type 9757, applies a specially designed low-frequency comparison coupler for the measurements.

Type 9757 is a calibration system designed to measure the frequency response of measurement microphones to very low frequencies. A specially designed, low-frequency comparison coupler allows the microphone to be fully inserted into the coupler cavity thereby ensuring that the static equalization vent of the microphone can be exposed to the applied sound pressure even for rear-vented microphones. Sound exposure of the vent during calibration is required if the microphone is intended to be used for free-field measurements.

USE SCENARIOS

• Low-frequency calibration of measurement microphones

FEATURES

• Frequency response calibration by comparison (IEC 61094-5) 0.1Hz to 251Hz
• Calibration of open-circuit or loaded frequency response (that is, response with preamplifier)
• Pressure-field or free-field calibration (that is, vent exposed to sound pressure)
• Dedicated PULSE project for controlling the measurements
• Dedicated Excel workbook for result calculation and presentation