Humidity Measurment thinger

[NuclearFusi0n]

Where can i get a nice humidity measurement thinger? I was told normal consumer dept store thingers aren't very accurate, and accuracy is important to me. thx.

 

[Cat13]

At work we use a swing thermometer to measure humidity on our aircraft engine runs. It is basically 2 thermometers, one measures temps and the other 1 has a cloth that you wet and slip over the bulb. It is hooked to a chain and swung around for 1 minute. Pretty cheesy but accurate, and easily replaced when the newbs sling it out of their hands!

I will get the part number and manufacture if you want.

 

[NuclearFusi0n]

is it expensive?

 

[Analog]

http://www.weatherequipment.com/taylor_thermometers.htm $26

http://www.davisontheweb.com/showpage.asp?L3ID=360 $29

 

[dullard]

Exactly what you should get depends on your needs. How accurate do you need it? What is your price range? What is the range of humidity you need to cover? You you need a fast response time? Etc.

The links yellowfiero gave didn't give many statistics on the meters they sell. Neither one said the accuracy, but one did say it has a very narrow range (30% to 90% humidity). Maybe that range is sufficient for your needs - or maybe not.

I opened up the Omega catalog and they have a really nice comparison of several types of meters they sell. Here is the online Omega site but it is much worse laid out than the actual catalog - and gives a bit less info. Since price is an issue I think the lowest priced one I see is the RH81 for $59. The product spec sheet link there tells you the accuracy: +-3% for most of the range, +-5% for extremes. Spend a bit more for the RH82/RH83 and the error is always +-3% and can measure the full humidity range from 0% to 100% and you get a bit more features. They do sell faster responding humidity meters, or some that have as low as +-2% error - but those are going to cost you.

 

[NuclearFusi0n]

edit: er i made a typo, need to measure 8 to 10%. i'd like to keep it hopefully accurate to +- 1 percent. any ideas?

 

[dullard]

Originally posted by: NuclearFusi0n
i'm looking to monitor humity from about 80 to 100%. i think i'll pick up an RH82 when i get the monies. thanks.

You are welcome. I've used Omega a lot and they are a pretty good company. Especially if you call their tech support for information on selecting your product. I once had many questions for a project and one of them spent 2+ hours on the phone going through all the details very carefully so that I get exactly the right product. The drawback is they take 1 week to ship it (then you have to add on shipping times).

I honestly don't know the % error from the two thermometer type of measurements like Cat13 mentioned. I bet it depends drastically on the accuracy of the thermometer. Since you will be subtracting two similar temperatures, the error is magnified. But maybe that will be sufficient for your needs.

 

[loup garou]

Hygrometer
Used to use these at my old job.

Search the Fisher site for 'hygrometer.' They sell tons more.

 

[Analog]

Originally posted by: dullard

Originally posted by: NuclearFusi0n
i'm looking to monitor humity from about 80 to 100%. i think i'll pick up an RH82 when i get the monies. thanks.

You are welcome. I've used Omega a lot and they are a pretty good company. Especially if you call their tech support for information on selecting your product. I once had many questions for a project and one of them spent 2+ hours on the phone going through all the details very carefully so that I get exactly the right product. The drawback is they take 1 week to ship it (then you have to add on shipping times).

I honestly don't know the % error from the two thermometer type of measurements like Cat13 mentioned. I bet it depends drastically on the accuracy of the thermometer. Since you will be subtracting two similar temperatures, the error is magnified. But maybe that will be sufficient for your needs.

good job. First time customers at Omega also get a free DMM. I order from them a lot here at my job.