hi,
im very interested in your humidity sensor, i would like to ask you, did you ever tried to connect it to PLC(programmable Logic Circuit)??
we tried your circuit, it is working, but how can we know if moisture is increasing or decreasing..
it is our primarily problem, we used your circuit as a sensor for server room.
hi,
im very interested in your humidity sensor, i would like to ask you, did you ever tried to connect it to PLC(programmable Logic Circuit)??
we tried your circuit, it is working, but how can we know if moisture is increasing or decreasing..
it is our primarily problem, we used your circuit as a sensor for server room.
You need to calibrate it with a known humidity level. Set it up alongside a calibrated humidity gauge, and measure the resistance of your home made sensor.
I wouldn't recommend this for any serious measurement...
There are numerous possible sources of error...
In your case (server room), temperature will prolly have a dramatic effect...
At the very least, the polarity thru the bridge should be alternating...
I would recommend the SHT10 or SHT11 parts...
They are capacitive pre-calibrated humidity sensors including a temperature sensor...
The interface is serial, you can find a control library on AVRfreaks.com...