2017 was our 20th year online!

Welcome to the Piano World Piano Forums
Over 3 million posts about pianos, digital pianos, and all types of keyboard instruments.
Over 100,000 members from around the world.
Join the World's Largest Community of Piano Lovers (it's free)
It's Fun to Play the Piano ... Please Pass It On!

Shop our online store for music lovers
SEARCH
Piano Forums & Piano World
(ad) Piano Sight Reading
train piano sight reading with your iPhone or iPad
(ad)
Best of Piano Buyer
 Best of Piano Buyer
(ad)
Pianoteq
Steinway Spiro Layering
(ad)
Wessell Nickel & Gross
PianoForAll
Who's Online Now
41 members (Bruce Sato, clothearednincompo, Archipelago, CyberGene, dima5222, Chapitrilfo, Calavera, 11 invisible), 365 guests, and 567 robots.
Key: Admin, Global Mod, Mod
(ad)
Estonia Pianos
Estonia Pianos
Previous Thread
Next Thread
Print Thread
Hop To
Page 1 of 2 1 2
#3107716 04/18/21 04:50 PM
Joined: Feb 2019
Posts: 70
F
Full Member
OP Offline
Full Member
F
Joined: Feb 2019
Posts: 70
I have a cheap hygrometer thermometer.
Also an automatic humidifier with built in hygrometer and thermometer.
The humidifier is on the floor and the hygrometer is on the piano.
The temperatures are within a degree or so of each other. Understandable being at different levels.
But the relative humidity readings are about 15% different.
What hygrometer would you recommend to get a more accurate reading?

Joined: May 2001
Posts: 5,076
H
5000 Post Club Member
Offline
5000 Post Club Member
H
Joined: May 2001
Posts: 5,076
Is the heating on? If yes here is a way that you can estimate the current indoors humidity.

Quote
Without humidification there is no way that indoors humidity can be higher than the outside humidity, when outside air is heated to comfort level of say 68F indoor temperature.

Just look for the current temperature and relative humidity from your weather site.

Open a psychometric chart and find the cross section point for the outside temperature and relative humidity.

Now move horizontally to right until you reach your room temperature and find the relative humidity curve that intersects it. That relative humidity is about your indoors humidity without any humidification.

Joined: Feb 2019
Posts: 70
F
Full Member
OP Offline
Full Member
F
Joined: Feb 2019
Posts: 70
Outside temperature is 7C (45F) & 55% humidity.
Inside is about 17C (63F).
That means my rooms humidity cannot be more than about 40% RH without using a humidifier.
My hygrometer is reading about 50%.
The humidifier is targeting 65% with a low setting, so it spreads the humidity more evenly through the house.

Joined: May 2001
Posts: 5,076
H
5000 Post Club Member
Offline
5000 Post Club Member
H
Joined: May 2001
Posts: 5,076
With those numbers I find it from the chart as 30% not 40%.

Joined: Feb 2019
Posts: 70
F
Full Member
OP Offline
Full Member
F
Joined: Feb 2019
Posts: 70
Thank you.
Looking again, you are correct. 30% looks more accurate.
So having my humidifier on is correct?
And the 50% reading of the hygrometer is probably more accurate than the 65% of the humidifier?
(The readings fluctuate a bit, 48-52%, 60-65% respectively).
Nothing feels damp and no condensation on windows.

Joined: May 2001
Posts: 5,076
H
5000 Post Club Member
Offline
5000 Post Club Member
H
Joined: May 2001
Posts: 5,076
You can use the below values for maximum indoors humidity for the respective outside humidity values, so that there won't be condensation etc.

Quote
If room temperature is 70F:

Outside
Temperature ——- Indoor Humidity

Higher than 50F — Max. 50%
25F to 50F ————Max. 40%
0F to 25F ————-30% - 40%
-20F to 0F ————20% - 35%
Below -20F ——— 15% - 25%

For 63F indoors temperature you might be safer.

Last edited by Hakki; 04/18/21 06:08 PM.
Joined: May 2001
Posts: 5,076
H
5000 Post Club Member
Offline
5000 Post Club Member
H
Joined: May 2001
Posts: 5,076
Sorry for the typo, it should be for the respective "outside temperature" values.

Joined: Jan 2006
Posts: 2,859
D
2000 Post Club Member
Offline
2000 Post Club Member
D
Joined: Jan 2006
Posts: 2,859
Fenner, the air has been particularly dry in the UK these last two weeks. If you have the heating on, I wouldn't be surprised if 30% indoors is correct. These frosty nights are precisely the time of maximum danger, when use of a humidifier is most important.

Joined: May 2001
Posts: 5,076
H
5000 Post Club Member
Offline
5000 Post Club Member
H
Joined: May 2001
Posts: 5,076
You should test your hygrometer with a bottle cap of slightly damped potassium carbonate in a sealed bag and calibrate it accordingly.

Until then your room could be at 50% or 65% or some other value depending on how much water the humidifier is putting into the room.

Joined: Feb 2019
Posts: 70
F
Full Member
OP Offline
Full Member
F
Joined: Feb 2019
Posts: 70
I don’t think I can calibrate my hygrometer. It’s a cheap one.
What one would you recommend that can be calibrated?
AcuRite and Caliber are 2 makes that get recommended by reviewers.

Joined: Aug 2019
Posts: 849
500 Post Club Member
Offline
500 Post Club Member
Joined: Aug 2019
Posts: 849
You do not necessarily need to calibrate. You just need to know the offset at few measurement points.


Wise men speak because they have something to say; Fools because they have to say something. (falsely attributed to Plato)
Vlad,
Adult beginner
Joined: May 2001
Posts: 5,076
H
5000 Post Club Member
Offline
5000 Post Club Member
H
Joined: May 2001
Posts: 5,076
This one claims to have +/-2% RH accuracy with manual calibration option.

https://www.acurite.com/shop-all/we...or-temperature-and-humidity-monitor.html

Joined: Jan 2006
Posts: 2,859
D
2000 Post Club Member
Offline
2000 Post Club Member
D
Joined: Jan 2006
Posts: 2,859
Unfortunately, the web site just says:

"AcuRite.com is currently unavailable in most European countries. We are engaged with the issue and committed to looking at options that support our full range of digital offerings to the EU market. We continue to identify technical compliance solutions that will provide all users with our time, temperature, and weather solutions."

This is despite the UK not being in the EU market!

Hakki, could you tell us if there is a model number for this? Then I could try it on Amazon.

David-G #3107844 04/19/21 04:23 AM
Joined: Feb 2018
Posts: 1,370
G
1000 Post Club Member
Offline
1000 Post Club Member
G
Joined: Feb 2018
Posts: 1,370
Originally Posted by David-G
Unfortunately, the web site just says:

"AcuRite.com is currently unavailable in most European countries. We are engaged with the issue and committed to looking at options that support our full range of digital offerings to the EU market. We continue to identify technical compliance solutions that will provide all users with our time, temperature, and weather solutions."

This is despite the UK not being in the EU market!

Hakki, could you tell us if there is a model number for this? Then I could try it on Amazon.

I can thoroughly recommend the Govee room thermometer/hygrometer which was accurate to 2% RH (within the range we are interested in) out of the box and is a data logger which pairs with a phone app as well. Having a conventional hygrometer is of relatively limited use because you don't look at it very often but you get pretty graphs showing how RH varies with time and seasons if you have this.

Alternatively if you don't want a logging facility it is worth considering the Inkbird humidity controller. That has an accurate hygrometer and high/low power outputs so you can connect it to humidifiers and stuff for a DIY damp chaser or whole room equivalent.


Both of those are available on Amazon.

P.S. It isn't really necessary to calibrate either of these as they are accurate enough out of the box (it is after all swings in RH we are really interested in not the absolute value). But if you do set it use Potassium Carbonate to calibrate at 43%, if you calibrate with normal Salt at 80% the non-linearity of the instruments means that at the 40->50% we are really interested in the device will be *less* accurate than as originally supplied. That was the case for the three instruments I tested anyway. Also of note is that the hygrometer on the Meaco dehumidifier I have is surprisingly accurate and there is also a surprising difference between the RH at floor level and that on top of the piano. I can give you some Potassium Carbonate if you just want a small quantity for calibration.

Last edited by gwing; 04/19/21 04:27 AM.
David-G #3107860 04/19/21 05:57 AM
Joined: May 2001
Posts: 5,076
H
5000 Post Club Member
Offline
5000 Post Club Member
H
Joined: May 2001
Posts: 5,076
The model number is 01083. It appears on Amazon.

gwing #3107861 04/19/21 05:59 AM
Joined: May 2001
Posts: 5,076
H
5000 Post Club Member
Offline
5000 Post Club Member
H
Joined: May 2001
Posts: 5,076
Actually we are interested in the correct Rh as well other than the swings.

So it is required to calibrate the hygrometer with the potassium carbonate method.

Hakki #3107864 04/19/21 06:28 AM
Joined: Feb 2018
Posts: 1,370
G
1000 Post Club Member
Offline
1000 Post Club Member
G
Joined: Feb 2018
Posts: 1,370
Originally Posted by Hakki
Actually we are interested in the correct Rh as well other than the swings.

So it is required to calibrate the hygrometer with the potassium carbonate method.

I do admit to being interested but the of the four digital hygrometers I checked two were within 2%, one within 3% and one (a really cheap one) within 4% so all were more than accurate enough already for piano keeping purposes. Admittedly they were all a lot loss accurate at 80% RH but that isn't of much concern.

Joined: Feb 2019
Posts: 70
F
Full Member
OP Offline
Full Member
F
Joined: Feb 2019
Posts: 70
I currently have a ThermoPro TP49

Joined: Sep 2018
Posts: 141
Full Member
Offline
Full Member
Joined: Sep 2018
Posts: 141
Might be worth investing in a wet and dry bulb hygrometer as they do not appear to be expensive.

Joined: Feb 2018
Posts: 1,370
G
1000 Post Club Member
Offline
1000 Post Club Member
G
Joined: Feb 2018
Posts: 1,370
Originally Posted by FennerMachine
I currently have a ThermoPro TP49

Send me an SAE and you can have some Potassium Carbonate to check it. Then even if it cannot be calibrated you can allow for its innacuracy. Or just buy this
Logging Hygrometer

Note this isn't the actual model I own and have tested, but it is less than half the price of the WiFi version and (probably) does the same job.

Page 1 of 2 1 2

Moderated by  Ken Knapp, Piano World 

Link Copied to Clipboard
(ad)
Faust Harrison Pianos
Faust Harrison 100+ Steinway pianos
(ad)
Couch to Concert Hall
Couch to Concert Hall
(ad)
PianoDisc

PianoDisc
(ad)
Piano Life Saver - Dampp Chaser
Dampp Chaser Piano Life Saver
(ad)
Mason & Hamlin Pianos
New Topics - Multiple Forums
The real pop book v3?
by Sebs - 05/05/21 10:35 PM
1997 Young Chang G Model
by texasheat - 05/05/21 10:10 PM
An embarassing first piano lesson
by total_beginner - 05/05/21 05:56 PM
Grand piano geometry question
by TTWK - 05/05/21 05:48 PM
Queen Elisabeth Piano Competition 2021
by AndresVel - 05/05/21 04:44 PM
Download Sheet Music
Virtual Sheet Music - Classical Sheet Music Downloads
Forum Statistics
Forums42
Topics206,738
Posts3,090,220
Members101,421
Most Online15,252
Mar 21st, 2010
Please Support Our Advertisers

Faust Harrison 100+ Steinways

Dampp Chaser Piano Life Saver

 Best of Piano Buyer

PianoTeq Bechstein
Visit our online store for gifts for music lovers

Virtual Sheet Music - Classical Sheet Music Downloads



 
Help keep the forums up and running with a donation, any amount is appreciated!
Or by becoming a Subscribing member! Thank-you.
Donate   Subscribe
 
Our Piano Related Classified Ads
| Dealers | Tuners | Lessons | Movers | Restorations | Pianos For Sale | Sell Your Piano |

Advertise on Piano World
| Subscribe | Piano World | PianoSupplies.com | Advertise on Piano World |
| |Contact | Privacy | Legal | About Us | Site Map | Free Newsletter | MapleStreetMusicShop.com - Our store in Cornish Maine


© copyright 1997 - 2021 Piano World ® all rights reserved
No part of this site may be reproduced without prior written permission
Powered by UBB.threads™ PHP Forum Software 7.7.5