Hygrometer recommendations?

[Woody Sound]

Anyone have a recommendation for an accurate, reasonably priced hygrometer? The Accurite on the right is right on, 45. I bought the ThermPro (on the left) for another room. When that seemed to be off, I ordered another Accurite (in the middle). To make matters worse, Amzn does not accept returns on these. Hmm. I wish I could find something that's close within a couple of points.

[guido5]

I have two ThermPros that are quite closely matching each other. I don't dare get a third...

[icr]

I use a sling psychrometer. Never goes out of calibration, has lasted for years.

[KirkP]

I use a sling psychrometer. Never goes out of calibration, has lasted for years.

Good idea! I forgot my elementary school science experiment! Here’s a DIY. Since a sling is awkward indoors, I suppose one could use a fan. And perhaps you could use this to calibrate an inaccurate electronic device, to determine an offset to add or subtract.

Who Needs a Meteorologist? Measure Humidity the Old-School Way, With a Sling Psychrometer! : 9 Steps - Instructables

[Max405]

Anyone have a recommendation for an accurate, reasonably priced hygrometer? The Accurite on the right is right on, 45. I bought the ThermPro (on the left) for another room. When that seemed to be off, I ordered another Accurite (in the middle). To make matters worse, Amzn does not accept returns on these. Hmm. I wish I could find something that's close within a couple of points.

Woody, I have 3 of those on the right. Very accurate. And they run on a single battery FOREVER!
Joe D

[Midnight Blues]

I have three from different manufacturers: Aprilaire, Accurite and Oasis. All three give me different readings and they're in the same room right next to each other!

[Woody Sound]

Woody, I have 3 of those on the right. Very accurate. And they run on a single battery FOREVER!
Joe D

Very accurate? All three of those (two are Accurites) were sitting next to each other all day and read differently. (The one on the right is the correct one.)

[Woody Sound]

Good idea! I forgot my elementary school science experiment! Here’s a DIY. Since a sling is awkward indoors, I suppose one could use a fan. And perhaps you could use this to calibrate an inaccurate electronic device, to determine an offset to add or subtract.

Who Needs a Meteorologist? Measure Humidity the Old-School Way, With a Sling Psychrometer! : 9 Steps - Instructables

Thanks, that psychrometer stuff is cool, but I just want three units I can leave in three different rooms and check with a quick glace. (Bedroom, living room with baby grand, and guitar studio downstairs.)

[Bezoeker]

Anyone have a recommendation for an accurate, reasonably priced hygrometer?

That seems like asking for a non-sleasy lawyer.

I have been through maybe 8 different hygrometers and have no reason to believe that any of them can be considered accurate.

I am sure there is a serous challenge involved in making a hygrometer.

But all I can do is use three or four of them and do a rough average of the reported humidity levels.

Would love to find an accurate/consistent one.

[Max405]

Very accurate? All three of those (two are Accurites) were sitting next to each other all day and read differently. (The one on the right is the correct one.)

Yeah, like I said, I have 3 of the ones on the right. Very accurate. The one in the middle could be a defective unit. It happens. Especially in a $8 electronic device.

[QAman]

If you really want to find out which one is correct, follow this calibration procedure,

How to Calibrate a Hygrometer (Humidity Sensor) using the Salt Test

Or, you can take a cotton towel wet it down good, then ring all the water off and wrap the gage. After it stabilizes it should read 100%. We calibrate our lab hygrometers using both methods - and if they past both tests they are acceptable for continued use. If not, we adjust them.

Sent from my SM-P610 using Tapatalk

[Bill Eisele]

If you really want to find out which one is correct, follow this calibration procedure,

How to Calibrate a Hygrometer (Humidity Sensor) using the Salt Test

Or, you can take a cotton towel wet it down good, then ring all the water off and wrap the gage. After it stabilizes it should read 100%. We calibrate our lab hygrometers using both methods - and if they past both tests they are acceptable for continued use. If not, we adjust them.

Sent from my SM-P610 using Tapatalk

The Boveda calibration kits work well and follow the same principle as the salt test: Boveda One-Step Hygrometer Calibration Kit | Boveda(R) Official Site

[Bill Eisele]

I really like the SensorPush units that use WiFi to connect to an app on your smart phone. What's nice about them is that they allow you to adjust the sensor response within the app for humidity and temperature based on calibration tests. I use them inside my guitar cases as well as in rooms. You can also set alerts for both parameters. SensorPush

[DRS]

I found a Honeywell unit in the trash on a jobsite. Put fresh batteries in and did the salt calibration. It's non-adjustable but it reads 3% lower than true so that is a nice safety margin. It never gets too humid here but sometimes too dry.

[Max405]

I wonder if the Salt water trick would actually work to create supplemental humidity inside my hanging wall cases? From time to time I am away from home and my huge 9 gallon humidifier runs out of water (mainly because the poor single pane windows steal all the moisture when it’s REALLY cold outside).
I am gonna try it..
JD

[Bill Eisele]

I wonder if the Salt water trick would actually work to create supplemental humidity inside my hanging wall cases? From time to time I am away from home and my huge 9 gallon humidifier runs out of water (mainly because the poor single pane windows steal all the moisture when it’s REALLY cold outside).
I am gonna try it..
JD

Joe, That’s the idea behind the Boveda humidity packs: Old - Boveda for Wood Instruments - Boveda(R) Official Site. They contain salt solutions of different compounds, concentrations and masses to provide a relatively constant humidity level inside an enclosed space. They come in different humidity levels and sizes for your specific application. There is a size and recommended %RH of 49% for guitars and other wood instruments. Not sure how many it would take for your display cases but I think at least one of the guitar display cabinet makers uses them in their design approach. They aren’t cheap but I regenerate mine when they dry out since they provide two way humidity control and will take on moisture.

The salt solution is sealed off from the exterior of the pack so only pure moisture comes out of the pack. I would be very concerned about having an open container of salt solution near my guitars most likely leading to corrosion of the metal parts. Just my two cents.

[Max405]

Hi Bill.
Yes, I thought better of that idea and decided not to experiment with my wooden instruments. With metal parts..
I didn’t realize you can regenerate those Boveda packs.thank you for the great tip!
Joe D

[Bill Eisele]

Hi Bill.
Yes, I thought better of that idea and decided not to experiment with my wooden instruments. With metal parts..
I didn’t realize you can regenerate those Boveda packs.thank you for the great tip!
Joe D

Hi Joe,

Yes, they are easy to regenerate. I use some Tupperware like containers (I use Lock & Lock) that can be sealed with an air-tight lid and put water in the bottom of the container. Then use something to keep the packs up out of the water (I used the racks from some extra containers that I bought). It takes about a week or so for them to get back up to the starting mass of 60 grams. You can eyeball them or use a cheap digital kitchen scale. I only use the 72% packs because it's so dry here in Santa Fe that it takes that percentage to get up around 50% inside the cases. Here's a couple photos of my setup:

[va3ux]

I have 3 Acurite model 01083M and they are not only accurate but they hold their calibration very well. I chose this particular model ( 01083M) specifically because if can be calibrated, unlike many other models of similar price. Like "ICR", I used a sling psychrometer to calibrate mine but you can use the simple 'damp salt method' to calibrate and get just about the same results.



Do NOT trust the humidity level setting on a humidifier. After I got the Acurites I discovered that the lowest setting on my Honeywell humidifier - 35% - maintains an actual RH of 54% at 68 Deg F. I now just run humidifier periodically to keep the house RH in the 45 - 50% range.