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Periodicity: it is good practice to make the control whenever any variation of the operating conditions occurs, i.e.
variation related to the material and/or the temperature, which can cause pressure channel occlusions.
Command modes check
The activity evaluates the proper functioning of the command modes and their effects on the sensor.
This is implemented by feeding the sensor out of the line and performing the following operations: RESET
AUTOZERO, AUTOZERO, CALIBRATION.
Periodicity: every 2 years.
In the Tab. 10.3 the most common failures and troubleshooting are pointed out:
Failure
Possible causes
The sensor doesn't
• Pressure channel occlusion
signal pressure and
• Output stage failure
no alarm signal is
• Over Pressure from 106,5% to 200% of span
activated
(HM/HW)
The sensor alarm
• Broken primary element
signal is "HIGH"
• Input stage error
• Detected pressure value over threshold
(2 x FS)
The sensor alarm
• Cut cable / broken connector
signal is "LOW"
• Device not connected
• Broken supply
• Overvoltage
• Undervoltage
• Floating power supply
• Program sequence error
• Overtemperature on electronics
• Pin detachement
The CAL function
• Broken electronics
doesn't work
• Zero signal threshold out of range
• Broken connector/cut cable
The AUTOZERO
• Broken electronics
function doesn't
• Zero signal outside activation range
work
• Broken connector/cable
(only external autozero version)
• Wrong magnetic pen positioning
Transmitter not
• Broken electronics
communicating
• HART communicator wrongly connected
with HART
communicator
HART
• Broken electronics
communicator
• HART communicator wrongly connected
missing
• HART communicator database (DD) not
updated
80636B_MAN_HMF - HWF_05-2022_ENG
Tab� 10�3� Most common failures and troubleshooting
Troubleshooting
1 - Sensor power-off and disassembly
2 - Double check possible pressure channel occlusion and clean
it from residuals or material
3 - Do the AUTOZERO function. If the problem persists, send the
sensor to factory for repair
4 - Reduce the process pressure under the F.S. value
5 - Switch on the sensor off-line and slightly press with the finger
the membrane; if the output signal is stable, send it for
factory reparation
1 - Sensor power-off and disassembly
2 - If the problem persists, send the sensor to factory for repair
1 - Sensor power-off and disassembly
2 - Check the correct connection of power supply
3 - Check the electrical continuity between the female plug and
the power supply
4 - Check if the power supply level is within specifications
5 - Check voltage supply stability
6 - Check possible housing overtemperatures
Remove the reasons, wait till cooling down and switch on the
sensor
7 - If the problem persists, send the sensor to factory for repair
8 - If the sensor works fine, mount the sensor in the seat
following instruction manual
1 - Stop the machine
2 - Make the TOTAL RESET OF THE CALIBRATION VALUES;
if the value is outside ± 20 % FS, disassemble the sensor,
check and clean the hole, mount again the sensor and re-do
the CAL function
3 - If the zero is within ± 20 % FS, check cable and connector
4 - If the problem persists, send the sensor to factory for repair
1 - Check the correct magnetic pen positioning on the autozero
logo
2 - If the problem persists, stop the machine
3 - Make the TOTAL RESET OF THE CALIBRATION VALUES;
if the value is outside ± 40 % FS, disassemble the sensor,
check and clean the hole, mount again the sensor and re-do
the AUTOZERO function
4 - If the zero is within ± 40 % FS, check cable and connector
5 - If the problem persists, send the sensor to factory for repair
4. Check Power Supply
5. Verify HART communicator connection
6. Verify 250 ohm series resistor
5. Check Power Supply
6. Verify HART communicator connection
7. Verify 250 ohm series resistor
8. Verify HART communicator database
27
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