User's Manual

2-1

2. Theory of Operation

Principles of Operation

The NDIR (Non-Dispersive Infra-Red Spectroscopy)

measurement method is implemented in the DX6106

Optical Unit.

The device provides gases concentration measure-

ment based on the classical double channel optical

scheme (Fig. 2.1). One of the beams (measuring

channel) has the wavelength which is tuned to the

optical absorption line of the measured gas. The other

beam (reference channel) has the wavelength which is

out of the adsorption band of the measured gas.

Intensities of two light beams that passed through the

measured gas sampling cell are compared.

Theory of Operation

RMT LtdRMT Ltd

DX6106

Fig. 2.1. The principle of gas concentration

Light Emitters

Photoresistor

Gas Flow

Intensity

Wavelength

Intensity

Wavelength