B28050-410-000-RC (MANUAL FOR XD-I).doc
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5.1 Conversion Formulae:
C = %LEL of Methane Test Gas
R = Equivalent % LEL of Target Gas
S = Signal in milliamps
J = number from the table above
J
C
R
*
=
S
= 4 + 16 x
R
mA
100
e.g. Calibration for propane using 2.46 % Methane Test Gas
2.46 % Methane = 49.2 % LEL Methane
R = 1.67 x 49.2 = 82.2 %LEL Propane
S = 4 + 16 x 82.2 = 17.15 mA signal
100
5.2 Calibration Gases
Calibration gas flows of 0.5 litre/minute are acceptable.
Sudden changes in humidity as from dry calibration gases may have a small transient effect on signal,
usually gone within a minute.
Long exhaust hoses (more than six inches or so) may cause back pressure conditions at the sensor and
enhanced signal, especially at high flow rates.
6.
Wiring
Wiring is three wires, DC 24 V with one analog signal line.
Figure 4 Wiring Hoop-Up
