SICK GM32 - Measuring Method; Optics Layout and Functional Principle

10 GM32 · Technical information · 8011923 · V 1.4 · © SICK AG
Product Description (Details)
Subject to change without notice
2.1 Measuring method
2.1.1 Optics layout and functional principle
The GM32 multi-component analyzer is based on in-situ technology with opto-electronic
direct measurement. Measured values are recorded without contact directly in the gas flow
using a measuring probe protruding into the duct. Depending on the version, this has
either an open measuring gap or a gas permeable membrane insert (filter) through which
the gas mixture being measured flows - the active measuring path.
The GM32 SR-unit determines the concentration of the respective gases based on wave-
length-specific light absorption by the gas mixture in the active measuring path.
Light from the sender/receiver unit (SR-unit) illuminates the active measuring path in the
gas duct which is then reflected back again by a triple reflector at the end of the probe. The
beam splitter diverts the returning light to the polychromatic subassembly comprising a
condenser lens with slit diaphragm, optical grating and receiver element. The optical
grating dissects the returning light spectrally and maps it to the receiver element, a highly
sensitive diode array.
Fig. 1 Measuring principle
1 Emitter
2 Tracking mirror
3 Window
4 Reflector
5 Beam splitter
6 4-quadrants detector
7 Optical grating
8 Detector
1
A
2
8
5
5
4
B
A Swivel segment with filter and cell for check cycles
B Swivel segment with zero point reflector and blanking diaphragm
3
7
6