Troubleshooting

The analog output is always 0V or 0mA

Please check:

  • was zeroing performed (via pushbutton or Didgitaleingang)
  • zeroing was carried out at the right time (when the silo was empty when the power was minimal), otherwise the measured value decreases with decreasing level below 4mA or below 0V
  • Supply voltage to the DMS test (2.5V or 5V)
  • Output voltage of the load cell test (less than + - 1 mV)
  • Document http://www.me-systeme.de/docs/de/basics/kb-check.pdf Read

Is the sensor defective?

  1. Test the Sensor without amplifier by measuring:
  2. Measure the input resistance and compare the measured value with the value in data sheet; Measure the resistance between +Excitation and -Excitation; typical values ​​of sensors with Straingages are 350Ohm, 1000Ohm, 370Ohm, 390Ohm, 700Ohm
  3. Measure the output resistance and compare it with the value in the data sheet; Measure the resistance between +bridge output and - bridge output; typical values ​​of sensors with straingages are 350Ohm, 1000Ohm, 700Ohm;
  4. Measure the insulation resistance. Measure the resistance between bridge output and sensor housing. The resistance should be greater than 200 MOhm.
  5. Connect sensor to amplifier and switch on
  6. Supply voltage measured between +Excitation and -Excitation. Typical values ​​are 2.5V or 5V or 10V or 8.75V
  7. Measire the differential voltage at the bridge output (select multimeters range "mV"). Typical values ​​are -1mV to + 1mV. If a value of the order of 10mV is measured, then the sensor is probably overloaded. If a value of half the supply voltage is measured, then within the sensor is a cable break.