Teledyne 9700 - Flue gas analysis system - Manual (Page 17)

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Flue Gas Analysis System General Information
TELEDYNE BROWN ENGINEERING
Analytical Instruments
4.2 Recessed Secondary Controls
NOTE: The recessed potentiometric controls are provided for calibration
purposes. They should not be changed once calibration is estab-
lished.
• The SPAN control adjusts for manufacturing variations in
sensitivity between elements and for various gases.
• The ZERO control adjusts for zero meter reading with zero gas
(air) flowing through the sample cell.
• The ALARM control allows the point at which the unit goes
into alarm to be adjusted anywhere between 0% and 5%
combustibles as shown by the meter reading.
• (Optional) The CAUTION control allows the point at which the
unit goes into alarm to be adjusted anywhere within the range of
the instrument as shown by the meter indication.
4.3 Meter Trim
The small potentiometer (P5) located on the main circuit board below
the meter is used to trim the meter to full scale deflection at the rated
output. The potentiometric control is set at the factory.
4.4 Analog Output
An analog (voltage or current) signal is provided for remote monitor-
ing or recording. The type of signal is a customer option.
• Voltage Output
0–1 Volt full scale or less.
NOTE: The remote meter or recorder should have an input impedance
greater than 1K-Ohm.
• Current Output
One of the following milliampere outputs may be
provided: