User's Manual

Construction of Optical Unit

RMT LtdRMT Ltd

DX6106

Within the gas concentration varying scale, the output

signal of measuring channel changes by order of value.

To preserve accuracy at large measuring gas

concentrations it is necessary to use an external

amplifier with a variable gain. It is to coordinate the

amplified signal with an ADC range.

Alternatively, an attenuator may be used. The attenuator

can be based on a digital potentiometer chip or D/A

converter.

It is unnecessary if LEDs pumping current control

scheme is implemented.

3-11

Fig. 3.15. Output signal processing

+5V

DX6106 Optical Unit

Attenuator

ADC

Microcontroller

+5V

–5V