Slowly rising Proximity Data

Lukas Salzburger3

I am using the LDC1000 EVM with a custom inductor for metal analysis. There is no mechanical movement in my setup and the temperature in the lab is (nearly) constant. Nevertheless the Proximity Data value is slowly rising (~0.1 count / s).

Do you have recommendations on inductors for metal composition detection?

over 10 years ago

0 Natallia Holubeva1 over 10 years ago

TI__Expert 6550 points

Hello Lukas,

The rule of thumb is for the inductor to be approximately the size of the target and the distance between should not exceed 1/2 diameter of the coil. Q factor should at least >8. Please try setting Rp min and Rp max values to stabilize the proximity data.
Best Regards,
Natallia Holubeva

0 Lukas Salzburger3 over 10 years ago in reply to Natallia Holubeva1

Prodigy 50 points

Thanks, but I don't measure a distance, but the metal characteristics. The "Proximity Data" should be proportional to the eddy current losses, but the value is not stable.

0 Natallia Holubeva1 over 10 years ago in reply to Lukas Salzburger3

TI__Expert 6550 points

Lukas,

You are correct. Rp is necessary for metal composition detection. The following blog post is recommended: http://e2e.ti.com/support/sensor/inductive-sensing/f/938/t/295036

Best Regards,
Natallia Holubeva

Sensors

Sensors forum

Slowly rising Proximity Data