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What do I do?

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Sceadwian

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This is a sensor that came out of a microwave, it was in a small aluminum housing with 1/8th circular holes on the front side, the whole thing was very well shielded, simple small gauge three wire leads, the shielding on the cable is heavy duty braided stainless.

I've never seen anything like it in any other microwave before. The function of the two holes in one of the pieces has me curious. The contacts are welded not soldered so it was designed to work at high temperatures.

I'm guessing a rugedized humidity sensor of some kind? Anyone wanna take a shot at this one?
 
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Model of the microwave?

It really is a microwave moisture sensor. See here https://www.electro-tech-online.com...icles5Cwhy_microwave_moisture_measurement.pdf for a more complex explanation.

https://naldc.nal.usda.gov/download/8917/PDF

soem info I have from a service manual:
SENSOR COOKING CONDITION
Using the SENSOR COOK, SENSOR REHEAT or POPCORN
function, the foods are cooked without figuring time,
power level or quantity. When the oven senses enough
steam from the food, it relays the information to its microprocessor
which will calculate the remaining cooking time
and power level needed for best results. When the food is
cooked, water vapor is developed. The sensor “senses” the
vapor and its resistance increases gradually. When the
resistance reaches the value set according to the menu,
supplementary cooking is started. The time of supplementary
cooking is determined by experiment with each food
category and inputted into the LSI.

It seems there are two resistive elements, one measure moisture and the other humidity. (Microwave model Dacor DCM24)
 
Interesting, is this how my wasing machine 'knows' what programme to use to clean my overalls?
I spose that particular device would be very resistant to noise.
 
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Had time to Google a bit more, it's an absolute humidity sensor made by **broken link removed**.

Doubt it would be in a washer, dryer perhaps, my dryer has an automatic dry setting.
 
Sounds logical.

My washer says it can select the wash cycle appropriate to the cloths within it, doesnt say how it does it, might just weigh them.

Must be a truly hardened sensor if its meant to be inside a microwave, I bet the designers went through a few blown interface circuits before they got that to work.

It'd make a robust outdoor humidity sensor for a weather station.
 
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Interesting, is this how my wasing machine 'knows' what programme to use to clean my overalls?
I spose that particular device would be very resistant to noise.

Washing machines normally use pressure switches to determine water level. They are manufactured with two switches reacting on different water levels and controlled by a MCU.

Their function is easy: A pressure hose is connected to the pressure port of the switch and switches are activated by compressed air on a diaphragm.

Boncuk
 
My dryer has an automatic mode too, but it's 44 years old, the sensor is mechanical. Probably horse hair: **broken link removed** Adjustable too (Back panel)

3 cycles: timed heat, timed air, automatic
 
I have one of those switches laying around, I think I've seen one used for a hho generator.
I assumed that the auto mode used a fancy gizmo sensor, but it probably just uses the fill level switch.
Would I be right in thinking there will be at least 2 contacts, one for correct level and one for overfill.
 
I've got an idea what you should do.

Build a hygrometer with it and show us all how to make one.

It'd be a lot safer than some of the posts on youtube where people mess with magnetrons.
 
3v0, imagine for a second that it was the component asking the question 'What do I do?' get it now? :D

I still have to figure out how it operates dr pepper! I'll Google that a bit when I have time, which I never have enough of :) A 14 week old son is hard enough to work around free time! Despite the number and length of my posts I don't spend as much time online here as one would think, not at least without doing something else as well.
 
I have a phillips hygro sensor, its been in my parts box since 1989 when I got it, never got around to making that weather station.
It operates by capacitance, it varies a couple of hundred pF over its measuring range.
If I was sussing out the sensor you have I'd stick it on a capacitance meter and waft some steam over it.
Maybe later ones use a different sensing method, the fact that theres 2 heads implies just that, maybe the 2 heads form part of a bridge, one measures and t'other compensates for temp or something.
 
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Now that I'm sure of what it is it will probably just go my bits box until a need for it arises (if one ever does) nothing I want to mess with right now though I would like to know the theory of operation, I'll work that out if I ever need it => Thanks for the comments.
 
I did a little research.
They are capacitive, moisture collects on the dielectric of a capacitor leaking away charge and reducing capacitance with higher moisture.
There is also a heater within the sensor on ones found in microwaves to 'dry out' the sensor, the heater glows red when its on!
Some sensors by the sound of it ones with 2 heads like this one not only measure humidity but also 'sniff', they can detect smell and know when your soup is cooked when it 'smells' right, fascinating.
So if your sensor is one of these it might not be much good as a hygrometer, but you could make a gizmo that tells you when your socks meed changing.
 
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