Servomex SERVOTOUGH LaserExact 2950, Operator'S Manual

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SERVOTOUGH LaserExact Monitor, Operator Manual 02950001A_1
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Line position: The position of the line peak (maximum absorption) in samples of
the AD converter [0..63]. The value should be close to the reference line position,
which is given in the menu <Gas specific parameters> for the corresponding line.
The instrument automatically tracks the line, i.e. if it deviates more from the
reference position than a given value, the instrument adjusts the laser temperature
and thereby the wavelength.
Line amplitude: Relative measure of the peak of the absorption line of the second
harmonic signal. If this value approaches 0.5-1.0 the absorption is strong and
saturation of the AD converter may be very close (actual saturation initiates the
ERROR). In the region 0.01-0.1 the signal is good. Below 0.01 the signal is
approaching the low level below which line width cannot be measured and line
tracking is off.
Transmission (%): Indicates how much light the receiver detects in % of the
maximum value. If the optical windows or the mirrors are covered with dust and
the transmission drops below a pre-set level, a warning will appear on the display
of the SERVOTOUGH LaserExact Cabinet. The cell window or the mirrors inside
the cell may have to be cleaned (see Section 5.2.2). The warning will also appear
for improper alignment of the mirrors in the beam alignment chamber.
Gas temperature (°C): The temperature currently used to calculate the gas
concentration. It may be a fixed value set by the user, the value measured by a 4-
20 mA current T-probe or the value measured by the instrument itself optically or
electrically. Optically measured temperature is called Spectral temperature.
Electrically measured temperature is the temperature measured by the embedded
temperature sensors (only used when the gas temperature is equal to ambient
temperature) offset-corrected to be equal the ambient air temperature. In the
example above the gas temperature is set equal to the Spectral temperature.
These settings can be configured in the <Measurement configuration> menu.
Gas Pressure (Bar abs.): The pressure in Bar absolute currently used to calculate
the gas concentration. It may be a fixed value set by the user, the value measured
by a 4-20 mA current P-probe or the value measured by the instrument itself using
the embedded pressure sensor (mainly for O
2
instruments and only used when the
gas pressure is equal to the ambient air pressure). This is configured in the
<Measurement configuration> menu.
Dry conversion factor: Factor currently used to multiply the gas concentration if dry
basis conversion is selected (see Section 4.3.5). The initial (wet) concentration
reading may be converted to dry reading if the H
2
O concentration is known. If dry
basis conversion is not activated the factor is always 1.0.
Max. Direct: Maximum value of the direct signal in the levels of AD converter [0 -
4096]. This value together with Dark Direct determines the value of the light
transmission.