CODEL
OPS. 141
60
Issue : A
Revision : 1
Date : 14/06/18
Doc i/d :
0141/6
050028
7.2. Data Valid LED Out
If one or more fault conditions occur, the data valid LED on the front panel will
extinguish, the data valid relay will operate, and the instrument will automatically
enter the diagnostic mode to display the fault condition. The following fault
conditions are recognised by the instrument :
Transmitter detector saturated (D
TH
> 24,000), possible cause -
transmitter signal failure or incorrect gain adjustment.
Receiver detector saturated (D
RH
> 24,000), possible causes :
high ambient lighting
incorrect detector gain adjustment
instrument calibrated during high opacity conditions which
have now cleared
receiver signal failure
Low transmitter detector level (D
T
< 4,096), possible causes -
transmitter signal failure
Window contamination when 2kcal > kwkg and Auto Zero is not
inhibited, possible causes :
calibration conducted during unstable duct conditions
dirty windows
Incorrect signal levels for calibration Kcal >32767
!
If a fault condition is recognised by the instrument, the minutes,
hours and days averages will not be updated.