For calibration of all Sper Scientific digital sound meters and any sound meter with a ½" microphone. The 850012 Sound Level Calibrator is used to calibrate the sensitivity of the microphone and sound level measuring equipment. The design is based on the feedback method to ensure a highly stable sound pressure level. This compact and ergonomic sound calibrator conforms to ANSI S1.40-1984 and IEC60942 (2003) Class 1 standard, and is perfect for calibrating Type 1 sound level meters with 1/2" microphones. To use, simply place the calibrator onto the digital sound meter’s microphone, turn on the calibrator, and adjust the meter’s reading to either 94 or 114 dB. Operates at a frequency of 1KHz ±1% with an accuracy of ±0.3 dB for 94 dB and ±0.5 dB for 114 dB levels, and features a built-in battery indicator. Small and light, it is easily portable for field use. • Standard sound level settings at 94dB and 114dB • Low battery indicator • Harmonic wave distortion of ±3%. • Output feedback detection Works with the following Sper Scientific class 1 sound meters: Type 1 Sound Meter