Radio Shack and Set & Forget Hygrometer readings

[Dobbs]

I have a Radio Shack hygrometer in my Aristocrat as a secondary unit. I did the salt test right after I purchased it. It was within 1%. The problem now is that the RS reads 74% and the set-and-forget reads 64%.......a 10% differance!!!!! I have the RS unit possitioned at the same level as the S&F unit, and about 12" apart.

My question are.....

Do either of these units loose calibration over time (4-6 months)?

How can I test the Set-and-Forget unit?

Is there a possibility that having the 2 units in the same cabinet may cause problems between the two?

Thanks again,
Dave

[artie97]

What's the temp inside

any hygrometer can drift or lose calibration. do another salt test on the radio shack. if you still see a 10 point differance, contact Bob. whatever the problem is, he will solve it for you. BTW, a good investment for any of us to have is the Extech hygrometer with the salt calibration kit. best $100 I have spent. I use it periodically to check the calibration on my Aristocrat and Avallo cabinets.

[Dobbs]

Originally Posted by artie97

What's the temp inside

70 degrees - both units agreee on this

[barrister]

Dave, I concur with roncarlos on the Extech hygrometer, as I had a similar problem with several of the same brand of hygrometers reading all over the board. Got the Extech, calibrated it with the included calibration standards and was then able to determine how much the other hygros were off and marked them accordingly. FYI, some of the RS hygros can be calibrated. I'll be happy to send you the info if your interested.

[artie97]

I noticed on my Aristocrat that when the temp starts going up.I get different readings on all my hygros.Had to use the air conditioner full time.

I also have the Extech www.arlinliss.com worth every penny

[Bob Staebell]

Dobbs,
Any hygrometer can drift over time. The difference does seem to be a bit much. The easiest way to resolve "which is right" is to send both the Radio Shack & the Set & Forget to CMT for a calibration check. There are often very surprising results when both units are placed in a controlled environment. I will drop a loaner in the mail. email sent

Cheers,

Bob Staebell

[Blue Smoke]

Wow Bob, Now that's customer service at it's best

[Dobbs]

Originally Posted by Bob Staebell

Dobbs,
Any hygrometer can drift over time. The difference does seem to be a bit much. The easiest way to resolve "which is right" is to send both the Radio Shack & the Set & Forget to CMT for a calibration check. There are often very surprising results when both units are placed in a controlled environment. I will drop a loaner in the mail. email sent

Cheers,

Bob Staebell

Thanks Bob ,

I'll call you in the morning.

[artie97]

Dave before you ship out the the Set&Forget and RS.Put the loaner in and leave the RS in and you'll have an idea.Thats if the loaner is calibrated.