Hi, i want to ask about how to use capacitive proximity sensor to differentiate materials such as plastic, paper and glass. The sensor will detect the material and segregate the material. How to adjust the sensitivity of the sensor to detect each material? is it do adjust in the code or else?
Calibrate for each material.
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You need a capacitance measuring cell, you cannot determine materials that are just in proximity, you need
to actually measure the dielectric constant.
If you want good sensitivity you need parallel plates with the material inbetween, no airgaps, accurately known
geometry.
Glass + airgap = plastic, plastic + airgap = paper, you basically can't tell much without precisely
known geometry of the material sample.
There are other techniques to measure dielectric properties remotely using microwaves, but they all need
known geometry to give a meaningful number.
Also the dielectric constant varies significantly with moisture content, and many materials can absorb quite
a large percentage of moisture.
wvmarle:
Calibrate for each material.
So, basically how to calibrate fr each material?
Standard universal calibration procedure: take known input, record output. After that's done you can take an unknown input and based on the output you see tell what it is.
Your input is the material that you want to test for. Your output is whatever reading you get.