Recommendations for the Most Accurate Hygrometer
 

Please help me in my search for the most accurate hygrometer. My guitars hang on the walls of my basement studio all year round. I have good units for humidifying the guitars during the winter, so that is not an issue. My problem is trying to mearure the amount of humidity. I do my best to maintain the RH at 45 to 50%. I use one Radio Shack Hydrometer and two from Oregon Scientific. I have tried calibrating the Radio Shack model per the instuctions provided by a fellow forum member. I cannot get the hygrometer to read 75% in a plactic bag with salt. Consequently, I fear that my readings are inaccurate.

Therefore: who has experience with an extremely accurate hygrometer? I will spare no expense to properly humidify my guitars. All advice is certainly appreciated. Thank you for your time.

Dan

Here are some I am considering as a replacement for my 4 Radio Shack/Oregon Scientific units.

http://www.bkprecision.com/www/np_specs.asp?m=625

http://testproducts.com/safecart/pro...roducts_id/525

http://testproducts.com/safecart/pro...3ae49acb08d298

http://www.2dihydrometer.com/hygrometer.html

currently i am using the planet waves hygrometer, though i dont like their soundhole humidifiers, their hygrometer is great and from what i can tell, accurate. turns out my previous analogue hygro was way off. i just leave it on a shelf in the room where my guitars are kept in their cases. it was around 30 bucks i think, maybe a bit more.

at the same time, "most accurate hygromter" is an oxymoron, much like jumbo shrimp or easy financing. still, yu should be able to get a reasonable accuracy using the planet waves hygro.

A $25 Oasis from http://elderly.com/accessories/items/OGH2.htm. According to them, they've tested it against their analog hygrometers and it is accurate. I've been using it for the past 3 months and my guitar definitely has been kept in the preferred RH zone. It's been sounding great w/ no signs of whatsover of dryness. The heat has been on a lot where I live and the house is definitely very dry, but I use this to measure the RH in my guitar case and it's been good for me.

The capfull of salt in a baggie with your hygrometer will give you the plus or minus that your hygrometer is off. That's all you need to know to be accurate with your readings. The salt is always 75%. If your hygrometer reads 82%, then its reading +7. Simply subtract 7 from your hygrometers reading to get the actual humidity. It's really that simple. Good luck!

Thanks for the recommendations, guys. I'm currently doing the baggie/salt calibration to see if my hygrometers pass the test. If not, I'll look into other units recommended here. Thanks again.
Dan

Herb: I looked at your suggestions. I don't mind paying more, given what I have at stake, but do you have any personal knowledge about these products other than finding them thru Google?

For what its worth, I have tried:

Radio Shack 63-1032 - Accuracy good, price good, size too large for case

Radio Shack 63-1089 - Crap

Humicase Compact Hygrometer - Small, as accurate as the Radio Shack with about +/- %5 accuracy (yet typically reads right with the Radio Shack model); works great in my guitar cases (I have a humidifier in the guitar room but still have in case humidifiers (Planet Waves) as the result of shutting down the main humdifier during the day when I'm at the office)

Planet Waves Instrument Hygrometer - A little less reliable than the Humicase and somewhat bigger so less convenient for in-case use

Cheapo Kroger GE Thermometer / Hygrometer - Got exactly what I paid for -> crap

John Pearse K-Saire Humidifying System - about the nicest hygrometer. Trust it more than other short of the next one

Fluke 5020 - About the best darn unit you can find. Quite overkill mind you, but in my line of work, I have access to one and I can borrow it.

Generally speaking, I think you'll be hard pressed to get a hygrometer for under $100 that does much better than 5% accuracy. Also, most of these same units do much better at higher humidity than at reading lower levels so your accuracy will be less as you reach lower numbers. So if you calibrate on at the 75% mark and find your difference, unless you stay near 75% RH, your values displayed can be way off as you get to the lower humidities. Don't know this as a fact for all manufacturers just know this from testing some of the above units against the Fluke (I'm an engineer and I was bored).

Good luck.....

From what I recall this isn't true... if you are off by 7% on the salt test... that means your thing reads 7% over... you just dont simply add or subtract (it's relative)

At any reading, that would be 107% of the actual humidity level... in any case... the difference should be negligible

Please correct me if I'm wrong...

ever see those tv reporters broadcasting live under some palm tree in florida during a hurricane holding up an ipod-sized device with a wind sensor on it?

9 out of 10 times those are the kestrel weather meters. the one i have is here:

http://www.kestrelmeters.com/Kestrel...ter.pro?sNav=0

but this is the cheapest one i could find on their site that measure s humidity:

http://www.kestrelmeters.com/Kestrel...Wind-Meter.pro

i know there would not be many willing to spend that much, but there is a chance some on here would wager $129 against a $2-3k guitar. much like joeinlex with the fluke, i had this as a result of my ham radio tornado tracking days and didn't buy one especially for monitoring humidity for instruments, but it's very handy to compare my other hygrometers against. a very nice feature of the one i have is a min/max/logging memory so that i can spot trends and spikes.

/guy

You've hit the nail on the head. I strive for 45% to 50% RH, obviously far below the 75% benchmark. That could explain the inaacurate readings, correct? That being said, isn't there a good alternative to the Fluke 5020 which sells for $1,585.00?!

Last year, at the Nashville airport, a climatologist from NOAA struck up a conversation with me asking about my Taylor. (He had an old Gibson and had heard a lot about Taylor.) I mentioned the inconsistency of the hygrometers I had and asked him if he could recommend one that was less than the $300. He said he thought the B&K Model 625 was a good field unit, the one in the first link I provided. The other links are for units I found for comparison purposes.

Thanks, Herb. I am going to contact a few of these maufacturers and speak with them . The price of the unit that you recommended is reasonable.

German made with a good calibration booklet.
http://www.12fret.com/retail/accessories_pg.html

Ooohhh, I like that Hygrometer from 12th Fret. Very simple and elegant. Too many choices, now. ****!