Siemens FIDAMAT 6-G Operating Instructions Manual page 21

The FIDAMAT 6 measures specific to the substance class, not specific to the components. It
measures the sum of all organically bound carbon in a sample gas, but with different
weighting of the hydrocarbon molecules.
In the first approximation, the display is proportional to the number of C atoms in the
respective molecule. In practice, there are deviations, however. The display deviation for the
respective molecule is expressed by the response factor.
The sample gas is supplied to the flame ionization detector in the FIDAMAT 6 under
overpressure via a non-clogging fused-silica restrictor. In the detector, the hydrocarbons
contained in the sample gas are burned in an oxyhydrogen flame. During combustion, the
organically bound hydrocarbon part is ionized. The released ions are converted into an ion
current due to the existing polarization voltage between the two electrodes and is measured
with a highly sensitive amplifier.
The measured current is proportional to the number of organically bound C atoms of the
hydrocarbons in the sample gas.
A pressure regulator keeps the combustion gas pressure constant. The coordinated system,
made up of capillaries and pressure regulator for combustion air, keeps the sample gas
pressure constant.
After switching on the analyzer, the flame will be ignited as soon as a temperature of 155 °C
is reached in the FID. You can monitor the current temperature of the FID at any time via
function 2 "Diagnostic values" under "Flame."
The FIDAMAT 6 sends various messages to external devices via floating contacts:
• Maintenance request:
• Fault:
The measured value could be influenced. The device switches to another operating state
under certain circumstances (the combustion gas valve is closed).
Note
The sample gases must be fed to the device dust-free. To avoid condensation, in most
applications a gas preparation adapted to the measuring task is necessary.
See also
Warm-up phase and operating states (Page 4-5)
List of maintenance requests (Page 6-5)
List of faults (Page 6-6)
FIDAMAT 6-G
Operating instructions, 07/2006, A5E00478463
Fan failure (advance warning for measuring accuracy). The device continues to measure,
as usual. The measured value is not influenced.
hydrogen, combustion air and sample gas pressure, temperature, physical part, error in
the electronics (temperature).
Description
2.4 Mode of operation
2-7