Filter
Top Products
MEASURING PRINCIPLE
2 - 3
ETC00781(1) Series 100 e 10/2001
Gas intake connection
Absorption chamber
Compensation chamber
2.1.2 Opto-Pneumatic Measuring Principle
A thermal radiator generates the infrared radiation passing through a chopper wheel. This
radiation alternately passes through a filter cell and reaches the measuring and reference side of
the analysis cell with equal intensity.
After passing another filter cell the radiation reaches the pneumatic detector.
The pneumatic detector compares and evaluates the radiation from the measuring and reference
sides and converts them into voltage signals proportional to their intensity via a preamplifier.
The detector consists of a gas-filled absorption and a compensation chamber which are
interconnected via a flow channel.
Fig. 2-2: Principle Design of Gas Detector
Flow channel with
Microflow sensor
IR MEASUREMENT
CaF
2
Window