Perguntas frequentes FAQ

How can the proper functioning of a load cell be verified?

To verify the correct operation of one or more load cells, tests should be performed using a digital multimeter with mV range. The test must be performed by qualified personnel able to perform the measurements accurately. We can see in detail the tests to be performed: 

Load cells resistance measure by means of digital multimeter:

  • Disconnect the load cells from the instrument and check that there is no moisture in the cell junction box caused by condensation or water infiltration. If so, keep cleaning the system or replace it, if necessary.
  • The value between the positive signal wire and the negative signal wire must be equal or similar to the one indicated in the load cell data sheet (output resistance).
  • The value between the positive excitation wire and the negative excitation wire must be equal or similar to the one indicated in the load cell data sheet (input resistance).
  • The insulation value between the shield and any other cell wire and between any other cell wire and the body of the load cell must be higher than 20 Mohm (mega ohms).

Load cells voltage measure by means of digital multimeter:

  • Take out the load cell to be tested from underneath the container, or alternatively, lift the container support.
  • Make sure that the excitation of two wires of the load cell connected to the instrument (or amplifier) is 5 Vdc +/- 3% (10Vdc +/-3% for instruments series TPS- TPZ).
  • Measure the response signal between the positive and the negative signal wires by directly connecting them to the multimeter, and make sure that it is comprised between 0 and +/- 0.5 mV (thousandths of a Volt).
  • Apply load to the cell and make sure that there is a signal increment.