Troubleshooting a switch that does not detect product

Verify coverage at the sensing region

Confirm that the medium reaches the active tip rather than stopping inside a nozzle or flowing past another part of the body. In bulk solids, a void or channel can leave the tip uncovered even when the vessel contains material.

A poorly wetted or low-dielectric product may require a different configuration or technology. Compare the actual medium with the suitability evidence used at purchase.

Check power and signal compatibility

Use the manufacturer’s diagram and qualified test procedures to confirm the supply and the receiving input. A local LED state and a PLC indication are not the same evidence. Check output type, logic, permitted load and the controller program before concluding that the sensing element has failed.

Retest in controlled conditions

Where permitted, compare clean air and a known representative product sample, then the actual process residue and temperature. Keep the results with the complete order code. If the device is damaged or the response cannot be made reliable within its documented capability, replace or reselect it rather than forcing an unsafe setting.

What to confirm for your application

• Actual coverage at the active tip
• Medium and temperature used for selection
• Supply and output compatibility
• Controller interpretation
• Supplier review of damaged or unsuitable equipment