Official Luthiers Forum!

Christmas is coming, and I may get a present this year!
So, thinking of what I might want, a hygrometer would be nice for the shop. Any suggestions on what is a good one? I notice Stew Mac has one, says "NEW" on their website. Does anyone have any experience with this one?

Open to suggestions, thanks!

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Phil

http://www.oleninstruments.com

"Those who tilt at windmills are only considered insane by those who can't see the dragon."

There was a thread here a while ago that recommended the ones you can get from Burgess Violins. Hit their site and scroll to the bottom and find Humidity Control Products....

someone posted info on how to make a "bicellulitic strip"(i made that word up: 2 strips of wood laminated together)that acts as a humidity indicator. i have been watching and charting mine for over a year, and it seems pretty great. i have it up against paper, and i have been putting marks on the paper as it bends through the seasons- a very large and dramatic swing. so while it has no numerical scale to tell you what the relative percent humidity is, if you calibrate it over time, ie, note where the bends are at given humidities, it looks like it could actually be pretty reliable as an instrument, certainly as a backup. it does seem like it should "wear out" or fatigue after awhile and no longer go through the full range of motion, but so far it seems good. i'll get a pic of it this week. batteries not required.
i used poplar end grain and maple long grain

The trick with hygrometers is to buy several of them ...that way you stand a better chance of one of them giving the reading you desire ...

I sprung for an Abbeon (http://www.ambientweather.com/ababhtab169.html) a long time ago and it has been rock solid. I double check the readings with a sling psychrometer periodically and it has not required re-calibration in a long time. It's been a permanent solution.

Another device which has been totally reliable is a Green Air humidity controller for humidification and de-humidification. (https://greenair.com/old/humidistat.htm) The sensors on the actual humidifiers and de-humidifiers have never seemed very accurate to me. This thing has worked great for several years.

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It's not what you don't know that hurts you, it's what you do know that's wrong.

Same as Terence, except I got the HTAB176 (white face). Works great. Expensive but worth it for the accuracy and good looks . I got mine for 30% off at Ambient Weather. I found out that the cheapo cigar box humidifier I had been using was reading about 10-12% lower than it should be. I still need to get a sling psychrometer.

+1 for the Abbeon, and/or a wet-bulb setup for the cheap route. I've found a wide range of accuracy with the ~ $20 electronic ones, some accurate only in certain ranges or temperatures. Typical that what I originally spent on cheapo electronic ones could have taken a chunk out of the cost of an Abbeon.

Pat

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formerly known around here as burbank
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http://www.patfosterguitars.com

Abbeon is currently out of stock on the $169 sale price hygrometer. I have 3 digital battery hygrometers , but can/t tell which one is accurate?

Put them in a plastic food container with wet Potassium Carbonate. Wrap the lot in plastic wrap/cling film to ensure that the external environment really is excluded. Take the readings after 8 hours or so. The nearest to 43% is the most accurate at that humidity level. Who cares if they aren't that accurate at 30 or 70%, it's the 40 to 50% range that matters. . . unless you live in an unusual environment.

grumpy is far too self-effacing to come on here and provide links to his ground-breaking contributions to RH measurement, but I have no such qualms.

Read all you need to know about RH measurement, and hygrometer calibration, Here, and here

Nobel prizes have been awarded for far less meritorious achievements IMO ...

Michael we have extremes here in the midwest lows of 5-10 deg f with 20% humidity in winter, and 85-100 deg F in summer with humidity from 65-70 % depending on the dew point .It is hellish climate for a gtr loofier.

I bought a Hygroset that was adjusted and guaranteed to be accurate

That's not uncommon although the lowest I've registered here is 25% RH. That usually occurs when the snow comes. 70% + fairly common in the summer.
The point that I was making is that those are towards the extremes. I only need my hygrometer to be accurate in the 40 to 50% range. That's the range I build at. I know that if the Hygrometer dips anywhere below 40% something needs to be done. Over 50% is a little less serious (in terms of cracks) but again, as soon as it goes above 50% the dehumidifier needs to kick in. It's the traffic light or stop go approach.

thanks michael I get your point!. I don/t know how does one get potassium carbonate ?. But definitely will start looking for another hygrometer

You get potassium carbonate from a supplier of soap making materials (some people make soap at home and there are suppliers for that). A pound is a lifetime supply and it's pretty cheap.

Thanks bob, for the explanation, will look into hygroset.

I obtained mine from Ebay. Small amount that will last a life time. It was pretty cheap. probably the equivalent of $10 US.

I just ordered 3 of the stew mac new ones.I will put them all in the same place for a while and see what happens.I will post what happens Donny

I've just tested my digital hygrometer against a sling psychrometer. I tested it with the Pot. carbonate last year. 7 years old and still within 3% of where it's supposed to be. I think it cost me £20 UK. It's perfectly possible to get cheap accurate hygrometers but you might have to return a couple before getting hold of a good one.

Hey Michael where did you get your sling? I think I should break down and get one.

Can't remember. Just buy a good thermometer and use a vacuum cleaner to pull air across the bulb. Then wrap the bulb with a bit of damp/wet cloth and do the same. There should be some tables online that help you work out the RH. I've dismantled my sling and I'm using one of the thermometers from it. I only use it once per year to check that my Hygrometers haven't gone too far out.

Nice one Murray, even nicer Mario.
So simple and inexpensive.
Gives me a cross-check with my saturated Potassium Carbonate.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

got my 3 from stew mac. two were 1% apart and the third was 3%--4% from them.not to bad I guess.there was no paper work at all,just in little boxes.I like the big dials.cheers,Donny

I picked up a dial type from an online weather related store.It was pricey. Over the years I used digital hygrometers and was never sure of their readings. Battery's would weaken and readings would be all over the place. Even with good batteries it seamed that the readings would be jumpy and non consistent I would even get two different readings if i put both of them in the same place in the shop...Mike

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Another day, another dollar.