8
SD2-NH3
40-200 mV
mVDC
Black
Red
-
+
Gas sensing element
Span adjustment
Pump
Solenoids
Fresh air sample port
Hosebarb connection
for sample air port
Top sensor board:
Fault (red) LED:
•
On steady if supply voltage is less
than 10VDC.
Status (amber) LED:
•
Blinks once per second if RFI is
detected.
Power (green) LED:
• On steady to Indicate Power.
•
Blinks once per second for 60
seconds during power-up.
• Blinks once per second
continuously if supply voltage is
too low.
Figure 3
Zero
adjustment
Bottom back board:
Status (amber) LED:
• On steady during room sample
• Blinks once per second during
fresh air purge.
Power (green) LED:
• On steady to Indicate Power.
•
Blinks once per second for 60
seconds during power-up.
• Blinks once per second
continuously if supply voltage is
too low.
• Blinks twice per second in
calibration mode (4 minute
timeout delay).
