Hygrometers are notoriously bad at measuring humidity. So tests have been created which anyone can do at home. Once you have done the test, you can know how off your hygrometer is in total relative humidity percentage. This will allow you to see how well Music Sorb is working for you my explanation.
How to Test a Hygrometer
1. Gather supplies. To test your hygrometer using salt, you just need a few household supplies.
A small food storage bag that zips
A tiny cup or bottle cap from a 20-ounce soda
Some table salt
Don’t add so much water that the salt dissolves; you just want it to be wet.
If you add too much, use paper towels to mop up the excess.
3. Put the cap and the hygrometer inside the baggie.
Zip it up and place it somewhere out of the way, so it won’t be disturbed during the test.
4. Wait 6 hours. During this time the hygrometer will measure the humidity inside the bag.
5. Read the hygrometer. If it’s accurate, it should show a humidity of exactly 75 percent.
6. Adjust the hygrometer if necessary. If your hygrometer shows a humidity lower or higher than 75 percent, you’ll need to calibrate it so that it’s accurate when you use it to check the humidity of your piano or instrument case.
- If you have an analog hygrometer, turn the knob to adjust it to 75 percent.
- If you have a digital hygrometer, use the buttons to adjust it to 75 percent.
- If you can’t adjust your hygrometer, take note of how many percentage points higher or lower than 75 percent it is. Next time you use your hygrometer, add or subtract a few percentage points for an accurate reading.
Some hygrometers are known to have fluctuations in accuracy over time. It is best to test a hygrometer every 6 months to maintain accurate readings.