Relative Humidity Sensor

Hi Guys,

I was wondering if you guys could perhaps help me, I'm looking for a humidity and temperature sensor, well temperature not so much, humidity is the most importan part. I have been looking at the DHT22, but my concern is I am measuring the humidity of an airstream that could be 95% or more and I have to have a large degree of accuracy in that range, even thou the DHT22 most likely have the accuracy the +-2% precision worries me abit.

I was wondering if you guys have any solutions to over come this, or could advise me on a sensor more suited to my needs.

Thanks

The DHT22 can be 30% inaccurate, or perhaps even more.

The Honeywell HIH6000 series is a lot better. They are 4.5%, which is a normal number for a good humidity sensor. The HIH9000 series sensors are 1.7% accurate for the range 10% to 90% RH. For exampe the HIH9131.

Thank you for that, however I'm expecting to measure %RH of 95% and more and measurement of accuracy is crucial. Will the HIH6000 still be viable?

I was looking at the rotronic HC2-SH it looks like it may be pertty good.

Thanks once again.

I don't know how accurate the HIH6000 or HIH9000 is at 95% RH. It is not in the datasheet. Those sensor are for consumer market.

The Rotronic HC2-SH has the Rotronic Hygromer IN-1 sensor inside. That is not ment for consumer products but for industrial measurements. Manufacturer page : http://www.rotronic.com/hc2-sh.html

The accuracy is 0.8% RH, and after calibration it is 0.5% RH. With a long term stability better than 1% RH per year.

Did you find a price somewhere for that sensor ? I read that the HC2-SH could be 1000 dollars. That is a "little" more than 10 or 20 dollars for the Honeywell HIH9000 series. Do you have the possibility to calibrate the HC2-SH ?

If you buy it and use it as it is, you should have 0.8% RH accuracy, but it gets a little more inaccurate every year.

Thanx, I am actually diong this for someone else, I will let them know that the only way of geting the accuracy of what they want is to fork out big moola. No I didn't get any prices yet, but I won't be suprised if it is around the 1K mark either.

Well thank you for your help. Much appreciated.