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In the August ’03 issue of Control Engineering, an article about non-contact level sensing titled ''Don't Touch That Process!'' drew some interesting reader comment that you may be able to address. One reader/subscriber wrote and explained that his past experience with non-contact thickness measurement of moving steel made him more aware of the sensitivity of inductive sensors to the distance between the sensor and the target metal.

In the August ’03 issue of Control Engineering , an article about non-contact level sensing titled ”Don’t Touch That Process!” drew some interesting reader comment that you may be able to address. One reader/subscriber wrote and explained that his past experience with non-contact thickness measurement of moving steel made him more aware of the sensitivity of inductive sensors to the distance between the sensor and the target metal.

He also said he liked inductive sensors because of their low ($50-$100) cost and high accuracy (

The reader believes that with creative placement and occasional re-calibration, inductive sensors could be used for level measurement. So with that as background, this reader asked, ”Is anyone using inductive analog sensors for level measurements?”

Send your thoughts and opinions to [email protected] and I’ll post them on our Web site.

—Dave Harrold, senior editor, Control Engineering, [email protected]