Review on Mengshen Temperature Multi Function Thermometer Hygrometer by Richard Simmons

Humidity is not very accurate and you cannot change the calibration constant. To be honest it has quite a large tolerance, the measurement takes more than a few seconds as the system needs to settle down. I use it within its capabilities, especially to check temperatures. The humidity is reduced by approx. 3% and increases depending on the value. I usually measure humidity around 45-65% with controls at 80%. I thought I would update the readings after 1 year of use. All measurements are slow, temp is still pretty accurate +/- 1F, humidity takes forever, the device turns off and I restart it but it's 8+% random, 5% otherwise no adjustment. These are great features at an affordable price, but only for temperature as humidity, wet bulb, dew point, etc. are all rubbish.