Siemens SIPROCESS GA700 Operating Instructions

4.6.2 How the CALOMAT 7 works
Overview
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① Sample gas inlet  
② Measuring membrane with
thin-󹪝lm resistors
 
③ Sample gas outlet  
Figure4-13 Principle of operation of CALOMAT7
How it works/measuring principle
The measuring method is based on the di󹪜erent levels of thermal conductivity of gases.
CALOMAT 7 analyzer modules work with a micromechanically produced Si chip, the measuring
membrane of which is equipped with thin-󹪝lm resistors.
The resistors contained in the membrane are regulated for constant temperature. The
amperage required 󹪞uctuates according to the thermal conductivity of the sample gas. This
raw value determined in this way is processed further electronically to calculate the gas
concentration.
The sensor is in a thermostatically controlled stainless steel enclosure in order to suppress the
e󹪜ect of the ambient temperature. To rule out 󹪞ow in󹪞uences, the sensor is mounted in a
bore hole next to the 󹪞ow channel.
4.7 Option modules
Option module 1.1
Option module 1.1 (OM1.1) provides eight additional digital inputs and twelve additional digital
outputs. Because the module is a "passive" module, the processing unit is in charge of controlling
the OM.
Option module 2.1
The option module 2.1 (OM2.1) is a "passive" module whose control is handled by the relevant
analyzer module. For every component measured by the analyzer module, the OM2.1 makes an
analog output available. This option module also provides three digital outputs per analyzer
module with a 󹪝xed function assignment.
Description
4.7Option modules
Wall-mounted device
38 Operating Instructions, 07/2023, A5E31930403-AB

Siemens SIPROCESS GA700 Specifications

General

Brand	Siemens
Model	SIPROCESS GA700
Category	Measuring Instruments
Language	English