Acoustic Calibrator

The HD 2020 sound level calibrator is a portable, battery operated sound source, suitable
for sound level meters (portable and laboratory) and acoustic stations. It allows calibrating
½”microphones with mechanical dimensions compliant with IEC 61094-1 (“Measureme nt
Part 1: Specifications for laboratory standard microphones”) and IEC 61094-4
(“Measurement microphones. Part 4: Specifications for working standard microphones”). The
calibration pressure levels of 94dB and 114dB can be selected by the keypad. The 1000 Hz
frequency cannot be changed.
1.  ON-OFF key: turns on and off the instrument. When you turn the instrument on, the display
will switch on about three seconds later.
2.  SETUP key: allows you to enter and scroll menu. To exit, press it repeatedly until you go
back to the standard screen.
3.  Display. When you turn the instrument on, it shows all segments on, and then the sound
pressure level (94 or 114dB) will appear in standard view.
4.   Calibrator cavity for conventional ½ inch microphones.
5.   Lower key: in standard mode, it selects 94dB and 114dB pressure levels alternately. In menu
mode, it decreases the current value.
6.  Upper key: in standard mode, it selects 94dB and 114dB pressure levels alternately. In menu
mode, it increases the current value.
7.   Battery lid.