Re: humidity sensors

Brett Lymn (blymn@awadi.com.au)
Mon, 30 Sep 1996 23:26:58 +0930 (CST)

According to Wim Osterholt:
>
>> I don't know if you can still get them but they were available > 10
>> years ago. I did have a circuit that used one that drove a panel
>> meter but it could be converted to feed an A/D....
>
>There have been packages build around a humidity sensor from Philips.
>Maybe you can't get that introduction package anymore, but recently I've
>seen that sensor still advertized. (Rather expensive. HFL40,- )
>

I think that is the one. The component I have is from Philips and I
do remember that it was quite pricey when I bought it back then.

>I have played with it in the past, but it really is terribly unsuitable.
>It's a synthetic foil, metallized at both sides. Since the humidity makes the
>thicknes of the foil vary, you have a capacitor of which the value will vary
>with the humidity.

Hmmm I did not know how it worked but now that you point it out the
thing probably is not the best thing in a condensing environment.

-- Brett Lymn, Computer Systems Administrator, AWA Defence Industries
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