1.4 Design and theory of operation
1.4.1 The instrument comprises the following main blocks and modules: radiation
detector; microprocessor; LCD; secondary power supply; IR-transceiver; and non-volatile
memory.
Backlight
driver
Quartz
generator
High voltage
power supply
DAC
of temperature
compensaton
Battery
1.5 V
RAM
Secondary
power supply
IR-
transceiver
Microprocessor
Audible
signal
Control
buttons
LCD
Radiation
detector
Figure 1.1 – Block diagram of the instrument
A Geiger-Muller tube with a filter for spatial-energy formation of sensitivity, which
converts photon radiation quanta to electric pulses, is used as a radiation detector. The
detector has a high-voltage power supply.
The microprocessor controls the instrument’s operating modes, backlight device,
audible, vibration and visual alarm devices, infrared communication channel, LCD, non-
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