M&C TechGroup SP2006-H280_DIL Operator's manual - Manual (Page 24)

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Gas sampling and gas conditioning technology 2-1.1.7.2-ME
W A R N I N G !
In the event of low temperature (failure of the heating) the supply of
dilution gas must be interrupted!
15.1 CALIBRATION
A calibration of the downstream analyser system or checking the dilution factor must always be ef-
fected under operating conditions.
Above the test gas valve, an appropriate test gas can be feeded.
N O T E !
The test gas pressure has to be higher than 0,7 bar, because the
pressure control valve has an opening pressure of 0, 7 bar.
When using the control panel, the respective ball valve for the test
gas supply has to be opened and the flow rate to be set on the
flowmeter.
The procedure for calibration or checking the dilution ratio is as follows:

Supply test gas of a concentration you know.

Check the dilution ratio on the downstream analyser and, if necessary, correct the pressure on the
pressure regulator of the dilution gas.
Test gas feeding without bypass injector
In order to assure that sufficient test gas is available, the test gas quantity should be at least threefold
of the flow quantity passing through the critical orifice (see injector data sheet).
Test gas feeding with bypass injector
The test gas quantity must be approximately 10% above the quantity of the volume flow passing
through the bypass (see figure 14) and the critical orifice (see figure 13).
16 CLOSING DOWN
Before closing down, i.e. switching off the heating, the probe should be purged with inert gas or air in
order to avoid condensation of aggressive components from the sample gas.
17 MAINTENANCE AND REPAIR
Before carrying out any maintenance and repair work, the specific installation and process safety
measures are to be observed.