ᐅ How can you reliably measure indoor humidity?

Hello,

I am trying to reliably measure the humidity in my basement. I currently have three hygrometers in use, but they show significant differences in their readings. For testing, I have placed all three devices side by side.

Here are the indoor readings:
1 (one that measures with an external sensor, but also shows indoor values on the device itself, manufacturer TFA Dostmann):
19.9°C (67.8°F) temperature, 70% humidity
2 (one that I can also access via an app and Wi-Fi, measures directly on the device, manufacturer HapopFan):
20.1°C (68.2°F) temperature, 63% humidity
3 (a very cheap one sold in sets of three for about 10 euros, measures directly on the device, very popular, manufacturer Thlevel):
20.0°C (68.0°F) temperature, 55% humidity

Do you have any idea which device might be the most reliable overall? Of course, you can’t tell for sure just based on these numbers, but I am open to buying a new one if necessary, as long as I get a dependable reading.

Regards

MarCologne schrieb:

Do you have any idea which device is overall reliable now?

Take a look at the user manuals of the devices. For example, TFA includes this information with their good devices (e.g., +/-3% between 35 and 75% relative humidity).

Many of them also need to be calibrated first (wrap in a wet towel for 30 minutes and set to 100%). Have you done that, or is this mentioned in their user manual?

Hello,

thanks in advance for your feedback.

I will check that, as I actually haven’t done it yet. So far, I only unpacked it, inserted the battery, and that’s it.
I will get back to you afterwards.

I have read through the instructions, but unfortunately, there is nothing about calibration.
Does it hurt to do it anyway? Probably not, right? Then I will give it a try.
Is there a reliable device for measuring, or can you recommend one?

MarCologne schrieb:

Is there a reliable device for measuring, or can you recommend one?

There are plenty of options. Many from TFA are reasonably priced and have an accuracy of +/-3% or better. But the manufacturer doesn’t really matter.