Signet 9900 Operating Instructions Manual page 50

Troubleshooting
Condition
Check Sensor
(pH/ORP only)
No Sensor
(Flow, Cond/Res, Press,
Level, Temp, 4-20 mA,
Sal, Batch, DO)
Check Preamp
Warning LED lit
Missing Cap
Replace Cap
Broken Glass (2751 Only)
Hi Impedance (2751 Only)
Check Cal
(2751 pH/ORP only)
50 9900 Transmitter
Possible Causes
9900 cannot "talk" to sensor
Missing sensor or bad temperature
element.
9900 cannot "talk" to sensor
9900 cannot "talk" to the preamp
Look for error message
Dissolved Oxygen sensor is missing
the sensor cap.
Dissolved Oxygen sensor cap has
expired.
pH/ORP sensor glass has been
damaged, causing very low
impedance.
The measured pH sensor impedance
is above the high impedance level.
Electrode could be in air.
Slope and/or Offset are out of range
(possibly due to memory failure in
sensor or preamp)
Suggested Solution
• Check wiring
• Install or replace sensor
• Check wiring
• Install or replace sensor
Check wiring or replace preamp
Correct error condition
Reinstall Dissolved Oxygen sensor cap
Install new Dissolved Oxygen sensor cap
Visually inspect pH/ORP sensor for
cracked and/or chipped glass.
Visually inspect the pH electrode and
clean if necessary.
Ensure electrode is submersed at all times.
Perform pH EasyCal (pg. 34 & 56)
Perform ORP EasyCal (pg. 36 & 58)
Set pH Slope or Standard (pg. 34 & 57)
Set ORP Slope or Standard (pg. 36 & 59)
Reset pH CAL (pg. 34)
Reset ORP CAL (pg. 36)