The incredible rising humidity hygro...

[Jwrussell]

I normally hate this, so I hate doing it, but this is a duplicate post. I've posted this on CW as well but I wanted the opinion of those here who don't frequent CW as well. TIA.

Anyone ever run into this before?

I have a radio shack remote system with three remotes and a base. Two of the remotes are pretty much spot on (1% off on one, spot on on the other) and one that reads quite high. Between 3-5% (I'm trying to figure it out now). Here's the deal:

I have a humidipak calibration kit that I'm using to check my hygros. I keep them in the pack for about 36 hours just to be absolutely sure they are on. The first two remotes settled down within 24 hours and pretty much sat still until I took them out around 36 hours. This last little fu**er, excuse my fr**ch

, is screwing with me. I had it labled at +5% (yeah, nice huh?) and yet it was reading low as far as I could tell on the top shelf of the wine cooler. I had it inside a half empty cab and it was keeping track almost perfectly with the hygro sitting on the shelf that reads spot on. In otherwords, when the hygro on the shelf hit it's top most RH reading (as it fluctuates out in the open air of the cooler) it would read the same as the hygro inside the cab. So, when I put this remote unit into the calibration kit, I decided to see if, for some reason, a temp difference was the issue. So I put the remote in the kit, stuck the kit inside the empty cab on top of the shelf and off we went. Here are my results:

Spot on to start with. 75%. Since then, over the past couple of days, it's crept upwards a point at a time to a current reading of 79%. It's been in there for 3 days now and I'm just leaving it there to see what it does. I just don't get it. It always reads perfectly within hours of being put in the calibration kit, but the longer I leave it in, the more it seems to creep up.

Any thoughts? I'm going to leave it in there for a week or so and see what happens. Depending on what happens I may try replacing the battery and recalibrating. If it's still doing the same thing it's probably going in the trash.

 

[Wasch_24]

Weird. It may just be wired wrong internally. :dunno:

I would suggest that maybe there is some condensation inside the hygro but when mine gets that it reads 98-99%. (it's outside)

 

[AZsteelman]

Nope, never had that situation and i have the same setup you have...

 

[Ratbert]

I just bought one of the Nexxtech remote hygros from Circuit City that were on sale and three remotes are all off by escalating amounts...but oddly enough, they're at +1%, +2% and +3%. Bizarre coincidence. I set them as remotes 1,2 & 3 to keep the variance straight in my head. Anyway, that's got nothing to do with your question, I know.

What I did when I performed my calibration was to put the remote into a 1 pint freezer bag along with a Boveda Humidipack tester...but I also put a Little Havana hygrometer in there that has been professionally calibrated and I know that it is accurate at +1%, no question. That way, I could compare the remote to the Little Havana and see the variance.

They would not always rise at the same rate, although after 36 hours they'd settle down to their correct variance and lock in.

If you have a smaller hygro that you've calibrated, place it in the humidipack as a control device along with the remote and see if your digital also creeps up and keeps pace. I agree with changing the battery and resetting the remote. It may just take longer to settle out for some odd reason, although several days is a bit much. If it's still rising, take it back and tell them to replace it with a new one.

Let us know what happens.

 

[Jwrussell]

Well, really freaky. The hygro keeps creaping up to the 78-ish area yet it matches spot on with the two self-calibrated units if I put them in another container. Even stranger, if I have just the self-calibrated unit in the humidipak bag then it reads spot on, but if I put the remote hygro in there with it then the s-c unit drops down to like 73%. Strange. Oh well, I'm gonna put together a salt test here at some point to double check, but in the meantime I'm just gonna go with all of them reading as they should.