Psychrometer/hygrometer equipment rec

[flukeynub]

I'm looking for information on hand held psychormeters/hygrometers and am wondering if anyone has had good experiences with particular brands/models. I'm looking for accuracy around +/-.5% RH for lab humidity transmitter validation.

Any recommendations?

 

[IRstuff]

"Validation" in what sense? What is your transmitter accuracy? Your tester ought to be 4x better, but that's assuming you need that level of accuracy to begin with


TTFN
faq731-376

 

[flukeynub]

Simply that, I want a hand held sensor to take to sample points near BMS transmitters to determine the drift/accuracy present. The plant transmitters are 10 years old and to my knowledge have never been calibrated post-base build.

I don't need high levels of accuracy as this not a critical process control HVAC application.

 

[DRWeig]

I've used hand-helds from Vaisala, they have been super.

Just like any other humidity sensor, get them calibrated at no more than one-year intervals.

Good on ya,

Goober Dave

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[KiwiMace]

You are probably not going to find +/-0.5% for a handheld. The vaisala unit mentioned above will do +/-1% up until about 90%RH and that is really good.
Most room sensors are good for +/-5% and some better ones do +/-3%, so a +/-1% calibration checker will be fine for your purposes. If you have higher precision sensors, then you need to remove them and calibrate them over a salt bath.
The real value in the handheld is that it can be readily calibrated, which is where you get your confidence in measurement.

 

[flukeynub]

Thanks for the info! Much appreciated.