- enter the coefficient n setting mode and the audible alarm on/off mode (hold
the button pressed for more than 4 sec);
- set (decrease) coefficient n in 0.1 steps in the setting mode;
- switch on/off audible alarm (press shortly for less than 1 s).
16 − LIGHT Button:
- turn the instrument off (press and hold the button until the LCD displays
“Off” message;
- activate LCD backlight;
- initiate infrared communication with personal computer;
- activate the coefficient n setting mode;
- increase coefficient n in 0.1 steps in the setting mode;
- switch on (Aud on) or switch off (Aud off) audible alarm in the setting mode;
- switch on (Vibr of) or switch off (Vibr on) headphones alarm in the setting
mode.
LCD indication:
15 − LCD upper line:
- count rate in count per second (s
-1
);
- messages “test”, “CAL”, “Aud”, etc;
- coefficient n value in the setting mode.
Analog Scale (not shown in the Figure) − 19 segments:
- time left until self-tests are complete: segments countdown the test time;
- time left until background calibration is complete: segments increase as the
instrument calibrates.
Low Battery Indicator (not shown in the Figure)-displayed when voltage
drops below 1.1V.
17 − LCD lower line:
- Relative root mean square uncertainty of count rate (statistical uncertainty) in
percent at 0.95 confidential probability;
- audible alarm on/off.
Block Diagram of the instrument is shown in Figure 2.
The instrument is composed of:
- detector unit;
- processor unit;
- audible alarm (headphones);
- power supply unit.