Water Level Sensors: Strange Behavior?

[Kaly]

HI All,

Has anyone experienced strange behavior with capacitive level sensor? They fail (not detecting fluid) at certain point and after leaving them alone for couple of days start working?

 

[berkeman]

HI All,

Has anyone experienced strange behavior with capacitive level sensor? They fail (not detecting fluid) at certain point and after leaving them alone for couple of days start working?

Can you provide a lot more details? Part numbers, datasheets, diagrams of the setups, schematics of the associated electronics, etc.? Thanks.

 

[Kaly]

Yes. please see attached image for specs for the sensor I am talking about.

 

[Tom.G]

They fail (not detecting fluid) at certain point and after leaving them alone for couple of days start working?

If "leaving them alone for a few days" means they are left dry, then they are probably leaking. Possibly due to mechanical strain, over-tightening, or manufacturing defect. Or maybe it is surface contamination.

The data sheet is not clear where or how the 'switching distance' is measured, 0.5mm from where? Could that be part of the problem?

 

[Asymptotic]

These sensors are being used for water level sensing, yes?
What appears to be an identical sensor found in a Google image search is titled a "Tintensensor" (ink sensor).

Is this clean, potable water? Is the probe end in direct contact with the water? What is the sensing application?

The data sheet is not clear where or how the 'switching distance' is measured, 0.5mm from where? Could that be part of the problem?

I'm thinking the question @Tom.G posed will be the key to explaining odd sensor behavior.

While attempting to find additional information on the MKM-M8-001-STD sensor shown in the spec sheet, learned that the www.sensorwelt.de site is no longer active, and the company appears to be in financial trouble. It may be time to begin looking for a replacement from a different manufacturer.