Hygrometer Test

[guit30]

I just got a new radio shack hygrometer last week. I can't get the humidity in my guitar case over 38 relative humidity, 74 degrees. Someone told me to check the weather report outside and see if the device was the same. I called the weather phone report which recorded 22 degrees with relative humidity of 40%. Now it was a couple of hours later that I tried it, but I sat it outside for about 5 minutes and I got 24 degrees and relative humidity of 28%, could it vary that much? Is that test valid?

Jim

[Dan Hall]

I just got a new radio shack hygrometer last week. I can't get the humidity in my guitar case over 38 relative humidity, 74 degrees. Someone told me to check the weather report outside and see if the device was the same. I called the weather phone report which recorded 22 degrees with relative humidity of 40%. Now it was a couple of hours later that I tried it, but I sat it outside for about 5 minutes and I got 24 degrees and relative humidity of 28%, could it vary that much? Is that test valid? Jim

Sounds valid to me. I would be pretty leery of RS electronic hydrometers. In the olden days you would have two thermometers mounted on a board with a swivel handle at the end opposit the bulbs. One of the thermometers had a wick on the bulb. Wet the wick then twirl the stick like a drum majorette for 30 seconds and the difference between the two temperatures could be converted into relative humidity. Funny how accurate that simple process is. RS is doing something with conductivity across a gap or on the surface of some sort of purpose built semiconductor, then they hire some folks who wear loincloths and ride home from work on a waterbuffalo to build them. Nice folks but there's a limit to how cheaply you can build things that work.

[guit30]

A lot of folk here say they are good, it was 20 bucks, I might just take it back, seems like it is not that accurate to me, What you reccomend for that amount, they all look the same

Jim

[bbarkow]

 

A lot of folk here say they are good, it was 20 bucks, I might just take it back, seems like it is not that accurate to me, What you reccomend for that amount, they all look the same Jim

 

Here's how I check mine:

 

How to salt test your hygrometer

 

Take a small container like a bottle cap, and fill it with salt. Make the salt damp with water (don't soak the salt completely). Place the wet salt and your hygrometer in a ziploc bag, and leave for 8 hours. Your hygrometer should read 75%.

 

You can then either adjust your hygrometer if you are able to, or just remember how many degrees off it is when looking at the display.

 

You should salt test your hygrometer every 6 months.

 

[Dan Hall]

 

A lot of folk here say they are good, it was 20 bucks, I might just take it back, seems like it is not that accurate to me, What you reccomend for that amount, they all look the same Jim

 

I dunno Jim. But I'm going to have to decide pretty soon because the Larri will be here tomorrow.

[nip]

I bought one of these:

http://www.tfa-dostmann.de/CD_2005/img/015.pdf

 

The one on the bottom of page. Transmitter fits nicely beside neck of guitar in case, and display in the room somewhere.

 

Where to buy in us I have no idea. But the company seems to have everything in the field hygrometers and related stuff.

[0rbitz9]

I have one of those Radio Shack hygrometers, and tested it with the salt test

method listed above the first day I bought it. It was reading low by 3%,

which I think was good enough for a $20 instrument. Here's a good link that

describes the procedure:

http://www.dukecitycigars.com/hygrometer.htm

 

I should also note that I later bought a Plantet Waves hygrometer, which is

much smaller and takes up less room in my case, but I don't like the user

interface of the Planet Waves unit at all.

[guit30]

I tried the salt test on my radio shack hygro and it was reading 18% low, so I took it back, they didn't have anymore, so I may just not get one til I find a better one. The good news is that my guitar is healing, the sponge and planet waves soundhole humidifier are doing their jobs and my action on the hi E is almost back to normal.

Jim