Fidamat 5E-As; Calibration; Automatic Calibration - Siemens FIDAMAT 5E Instruction Manual

7.1.3

FIDAMAT 5E-AS

With the FIDAMAT 5E-AS, the excess sample air is output from the analyzer via the bypass. In
calibration mode, the excess calibration gas is output via the gas outlet. Only one zero gas and one
calibration gas are available for the analyzer.
7.2

Calibration

The calibration should be carried out using gases whose composition is very close to the sample
gas. If it is necessary to measure methane in nitrogen, a calibration gas containing methane in
nitrogen should also be used. If, for example, propane in synthetic air were used as the calibration
gas in this case, the result would be falsified by the response factor of methane compaired to
propane and by the oxygen error.
The calibration can be carried out in two manners:
– Via the gas connections on the rear of the analyzer. The inlet pressure must be 3 bar above
atmospheric in this case
– Via the sample gas line, where the excess gas flows via a T-piece outside the analyzer.
In both cases, the setpoint for the span (function 7) must be entered prior to the calibration. This
value can be checked using function 6 - a value must always be entered with function 7. Ensure
before entering the value that the correct concentration unit has been selected, e.g. ppm C
ion 94).
The zero and span can then be adjusted using functions 5 and 8 (identifier 1 for all measuring
ranges). Excess calibration gas flows via the sample gas line in both cases.
With the FIDAMAT 5E-AS, the excess calibration gas flows via the exhaust line during the calibration
process. An external valve (shed valve) can be connected to prevent the calibration gas from flowing
back via the sample gas line (see connection diagram for FIDAMAT 5E-AS). To prevent an
overpressure from being generated in the analyzer, ensure that the excess calibration gas can be
discharged at atmospheric pressure.
7.3

Automatic Calibration

Calibrations with zero and calibration gases can also be carried out automatically. The automatic
calibration procedure is activated using function 22. Further parameter settings can be made using
functions 40 to 48.
Fig. 7.1 shows the timing of the automatic calibration procedure.
20
(funct-
3