Review on 🌡️ Efficient AcuRite Pro Humidity Meter & Thermometer with Touch Activated Backlight - Enhanced Accuracy and User-Friendly Interface, White by Douglas Holla

I put the batteries in and got 35% relative humidity. External relative humidity was 9%, which is typical of the Sonoran Desert. However, it is also characteristic that the air humidity in the desert is much higher. So I did a salt calibration and it showed 61% instead of 75%. In other words, this value was 14% below normal. The good news is that you can easily adjust the value. I increased the relative humidity by 14% according to the instructions, let it sit overnight, and then repeated the salt test. The Accurite hygrometer read 75% as expected. The next day the relative humidity was up to 19% outside and up to 47% inside. There are commercial 75% calibration kits (NaCL or table salt) and 35% calibration kits (CaCL2 or ice melt salt) to see how they perform at different humidity levels, or you can follow the instructions online using your own table salt. BTW: Morton Sea Salt is calibrated the same as Morton Table Salt (I've tried both), and it doesn't matter if it contains iodine or not. Update: As I use an Accurite hygrometer to monitor musical instruments, my main concern is its accuracy at 45% relative humidity. Cigars require relative humidity in the 60% to 70% range, so the salt test provides an accurate calibration close to desired conditions. But how "linear" is the Accurite hygrometer? Does a 75% calibration provide about 45% accuracy? I used a sling psychrometer to calculate my relative humidity using old school wet and dry bulb temperatures. The psychrometer showed 50% relative humidity, the Accurite hygrometer showed 48% relative humidity. This is within the margin of error for both the equipment and machinery, so no further adjustments were made. The mad scientist in me discovered that the potassium carbonate salt used in brewing has a relative humidity of 44% when used as brewing salt. salt test. I'll update these results when I find some potassium carbonate. Update: My hygrometer showed the expected 44% when tested with the potassium carbonate salt test. So my conclusion is that calibrating NaCl (table salt) at 75% humidity is all you need to do unless you are a home brewer and have some potassium carbonate on hand then you can choose which one.