TROUBLESHOOTING
8 - 6
each sensor when it was fabricated in the factory. If the
current date exceeds the expiration date of any sensor, the
performance of the given sensor can no longer be
guaranteed. It is strongly recommended that the user replace
the sensor immediately to ensure proper operation of the
sensor.
8) Adjust Pump Stall Threshold
This display can be used to calibrate the pump stall
threshold. If the gas inlet is blocked but the pump does not
shut down, or the pump shut down too easily with a slight
blockage to the gas inlet, then the pump stall threshold value
may be set too high or too low. Use the following steps to
adjust the pump stall threshold.
1. The maximum and average pump current is displayed on
the first row: “Pump = xxx/zzz”. The current pump stall
value is displayed on the second row: “Stall = yyy +/-”.
The typical maximum and average pump current without
any blockage should be between 8–10. The typical stall
value should be higher than the “un-blocked” pump
current by at least 8-10 counts.
2. The user can block the gas inlet and watch the pump
current reading. If the pump current reading does not
increase significantly (i.e. more than 3–5 counts), then
there may be a leak in the gas inlet or the weak or
defective.
3. Use
[Y/+]
or
[N/-]
key to increase or decrease the stall
value until it is about 8-10 counts above the “un-blocked”
pump current reading. Press
[MODE]
key to exit this
display. If the threshold value is changed, a message
“Save new stall threshold?” will appear. Press
[Y/+]
to
