Controls On The Front Panel - BRUEL & KJAER 4226 User Manual

8 Multifunction Acoustic Calibrator Type 4226 – User Manual
2.2

Controls on the Front Panel

Fig.2.1
The front panel of
Type 4226
•
Power:
Switch Type 4226 On or Off. Type 4226 is powered by four 1.5 V batteries
•
Batt. Low:
The LED lights up when the battery voltage is too low. When this happens, replace the four
cells in the battery drawer according to the instructions given in section 3.2.
•
Frequency Hz:
The LED indicates the test signal frequency or presence of an external generator. The LED
lights continuously when the sound level produced in the coupler is stable, and flashes when
unstable. The signals for these tones originate from a built-in generator.
Frequency setting is in ten octave steps from 31.5 Hz to 16 kHz plus an extra setting at
12.5 kHz. The frequency of the selected tone is indicated by its LED.
✐
The LED also flashes at the end of the 30-second period initiated via the Timer button.
Please note:
Use the Frequency Step to select Ext. Gen. When selected, the LED lights up and the signal
applied to the Ext. Gen. socket on the side panel will be reproduced acoustically in the
coupler. In this condition, the built-in signal generator is isolated and the frequency response