3 different hygrometers,3 different readings

[Rosewood99]

Three different brands within a foot of each other. One says 45%, One says 40% and one says 36%. Arghh!

[Martin_F]

These things are never very accurate. The good thing is, you don't need to be that accurate. As long as none of them say it's under 30-35% or over 70%, you should be ok. Ideally, you want to stay between 40 and 60%, but I have never heard of anything bad happens when things dip a little lower or a little higher. You really want to avoid the 10-15% humidity conditions. I know my hygrometer stops reading after my house goes down below 20% or so.

You really have to see if one of them is getting a breeze or something. Reading humidity is tough because it can change based on the wind currents in the area of the house (right by a vent or a door that leaks).

I have to say though, that is a pretty big variation for being close! What brand(s) of hygrometers do you have?

Martin

[mawmow]

To test these, put them on a wet towell and see how they read.

Anyway you should be okay should these three read within 40-60 % range

[Chipotle]

Originally Posted by paulzoom

Three different brands within a foot of each other. One says 45%, One says 40% and one says 36%. Arghh!

You can get a cheap calibration kit and see which ones are off.

[Big Band Guitar]

I have been in calibration and repair of industrial instruments for 39 years.

Unless your instrument is certified the readings are pretty much meaningless.

A certified hygrometer will cost you many hundreds of dollars.

To check your hygrometers against each other place them in a glass jar so you can see the dials/readouts, seal the jar and leave it over night. If the readings are within 10% of each other it's as good as it is going to get.

[john57classic]

Just FYI Paul, I think you mean hyGrometer.
And as has been mentioned the types of instruments we typically acquire have limited accuracy and limited precision, maybe +/- 3-5%. So I would consider the 3 readings you have there in pretty good agreement, especially if you haven’t done any calibration

[gibpicker]

I have a "fits in the strings" Music nomad that was within 1% of the radio forecast when set outside, so maybe I just got lucky, and I just leave it out on our computer station now. I could see it if it was off 1% or so, but not 5%.

[raysachs]

Originally Posted by Big Band Guitar

I have been in calibration and repair of industrial instruments for 39 years.

Unless your instrument is certified the readings are pretty much meaningless.

A certified hygrometer will cost you many hundreds of dollars.

To check your hygrometers against each other place them in a glass jar so you can see the dials/readouts, seal the jar and leave it over night. If the readings are within 10% of each other it's as good as it is going to get.

I trust your expertise, but my recent experience tells me things might be getting better. I recently got several Govee bluetooth hygrometers, that were all within fractions of a percent of each other after leaving them all bunched together on my desk overnight. Then I put one of them in a Boveda calibration kit with a little humidipak that is supposed to get the inside of the sealed plastic sleeve up to 75%. After 24 hours, the one I put in there was within 2/10 of a percent of 75%. I calibrated it to exactly 75, bunched all of them together overnight again, and in the morning they were again all within fractions of a percent.

Just to be silly about it, I calibrated them all to the one that had been in the Boveda kit and sent them out to their various guitar cases, cabinets, and locations in the room. A week or so later, I bunched them all on my desk again overnight and the next day they were all within 1/10 - 1/5 of a percent. At which point I figured that's WAAAAAY beyond close enough for monitoring my guitars. Maybe I'll repeat in 6 months or so just to see if they degrade over time, but they appear to be a whole lot closer than within 10%.

-Ray

[gfspencer]

In the old days before digital watches there was a saying - "When I only had one watch I knew exactly what time it was. Now I have two and I'm not sure."
Hydrometers are the same.

I have a number of hydrometers for cigar boxes. They are never exactly the same. Instead I look for a "range".

[Rev Roy]

Originally Posted by raysachs

I trust your expertise, but my recent experience tells me things might be getting better. I recently got several Govee bluetooth hygrometers, that were all within fractions of a percent of each other after leaving them all bunched together on my desk overnight. Then I put one of them in a Boveda calibration kit with a little humidipak that is supposed to get the inside of the sealed plastic sleeve up to 75%. After 24 hours, the one I put in there was within 2/10 of a percent of 75%. I calibrated it to exactly 75, bunched all of them together overnight again, and in the morning they were again all within fractions of a percent.

Just to be silly about it, I calibrated them all to the one that had been in the Boveda kit and sent them out to their various guitar cases, cabinets, and locations in the room. A week or so later, I bunched them all on my desk again overnight and the next day they were all within 1/10 - 1/5 of a percent. At which point I figured that's WAAAAAY beyond close enough for monitoring my guitars. Maybe I'll repeat in 6 months or so just to see if they degrade over time, but they appear to be a whole lot closer than within 10%.

-Ray

Thanks for doing all that research and sharing it with us in your previous thread, Ray. Made me a believer. I now have Govee units in my cases and the guitar room. So far so good. They are inexpensive and plenty accurate for guitar monitoring...

[KevinH]

Have you calibrated them? The Potassium Carbonate method isn't hard to do and will give you a RH of around 43% to check them all.

Edit: Missed the earlier responses that came in. My experience with SensorPush and Wireless Tag sensors is similar to Ray's. They all agree to well within their stated accuracy (2%).

[loco gringo]

I have a number of these. I calibrate them with the Boveda calibration package when I get them. I can set them next to each other and they will be with in 1 or 2 of each other. For instance three of them might read 41, 42, 43.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I may try the Govees that raysachs mentioned at some point.

[loco gringo]

Govee users, do you connect with them via bluetooth while they are in your case? If so, can you distinguish between a number of them?

The Amazon description says search for H5075 and pair. If you have more than one do you have to pair to each one individually one at a time to run through them? If so, how do you know which one is which?

EDIT: Ah, I didn't look far enough on the Amazon listing. I see they have them named Living Room and Bedroom on their example.

So, can you connect to them when they are in a case?

[dnf777]

My first impression was that those three readings were within a 10 point range. Close enough, and probably as good as can be reasonably expected Without significant outlay.

[edward993]

Originally Posted by gfspencer

In the old days before digital watches there was a saying - "When I only had one watch I knew exactly what time it was. Now I have two and I'm not sure."
Hydrometers are the same.

I have a number of hydrometers for cigar boxes. They are never exactly the same. Instead I look for a "range".

Agree wholeheartedly on all counts.

The last part is all one needs for guitars. Getting the a case or room's RH within a reasonable range is all that guitars need. It is far too easy to overthink this RH thing, really. Get the RH in the ballpark and avoid wide swings is all one needs to keep that wood healthy and stable.

Edward