Common Issues
Sensor reading is not accurate: Re-calibrate sensor, clean sensor, or replace sensor.
Sensor output in unstable: Check water flow rate. Check for electrical interference or loose connections.
Electricals
The APNTU will not power up. Check the power source or try a different power source. Check to ensure the power cable is properly inserted in the power receptacle.
No signal from sensor. Remove sensor and check connections. Clean sensor.
Check that all signal cables are shielded and properly grounded. Ensure signal wiring is not located or run next to high voltage power or equipment generating EMI. Ensure power wiring to the pump is clean/conditioned.
The 4-20mA signal is dropping or incorrect. Check the cables integrity and proper connection to the unit. Check that all signal cables are shielded and properly grounded. Ensure signal wiring is not located or run next to high voltage power or equipment generating EMI. Ensure power wiring to the pump is clean/conditioned.
The Display reads Error code. Follow instructions on the unit and contact the factory for assistance. Some error codes may be corrected with a current Firmware Update. See System section for details on firmware updates.
Instrument Alarms and Descriptions
Please refer to the instrument alarms and descriptions table when troubleshooting the APNTU online inspection system issues an alarm or indicates abnormal measurement data.
