Do they use capacitance to work? I read the manual and did a Google search, but couldn't come up with any information on them. The manual tells very little about them. Does anybody know anything more about them?
I am asking because I have a couple of them on the outside of a small container being filled by a pump. I use them for high and low level sensing to turn a pump off and on. The low level sensor is acting erratically. Sometimes sensing, sometimes not.
Just wondering if having a couple of the sensors close together could interfere with each other.
I have seen them, and I wanted to give it a try, but didn't order it after reading about it.
Perhaps ultrasonic or capacitive, I don't know. There are a few other options to detect water, even with RF or magnetic (like MRI).
It would be nice if an adjustable version was made, or with analog output, and with an absolute measurement. I read that it detects a relative change, so when it is powered on, it doesn't know if there is water or not.
All those possibilities (ultrasonic, capacitive, RF) do interfere with each other.
Ah, thanks. Makes sense. Thanks for your input. It confirms with my experience with these sensors.
The readings from the sensor seem to get erratic when they are somewhat close together, and/or when they first turn on near liquid.
They are easy to use, just digitalRead the pin they are attached to. My circuit works well when I test each switch on their own, the coding is super simple.
I agree it would be nice if they were adjustable to set a trigger point instead of just a preset relative change of what ever they measure. It would be nice if they put out an analog signal too instead of a digital off/on. That way, programming a trigger point would be easy. Also, it would be easier to see what the sensor is doing and measure any interference more directly instead of an on/off.
They work good and are simple to use on their own, but if using multiples, I would stay away. I will change them out for float switches or something else more reliable. The relative change also means that you cannot switch them on and off in turn to reduce interference from the other sensors.
Thanks for the input. Guess I will have to rig up a single capacitive sensor, or two float switches.
It's capacitive, think. Ultrasonic sensors can't measure trough wall an must mount on top of tank. I have some backgrounds from a job in a galvanic area
But capacetive sensors can made trouble with different liquids. DI water needs a different calibration like acid or rinse
Capsense does just that, with the provision that you have a resistor on one pin and the capacitance being sensed is on another. Nothing but one resistor and two pins required.
