Review on Accurate Indoor Thermometers Hygrometer - 2-Pack Temperature Humidity Monitor with Celsius/Fahrenheit - Ideal for Humidors, Greenhouse, Garden, Cellar, Closet and More by AikTryee (2 PCS) by Steve Collins

They showed two different temperatures - 4 degrees difference after sitting next to each other in the office room. Obviously had to be calibrated. However, you cannot calibrate them without removing the reverse gear. So I took the back off and put it in a glass freezer container, filled it with ice and put it in the ice maker (yes I am that guy). Pulled them out after 20 minutes and set them to 32 degrees Fahrenheit. It's quite difficult to get accurate information, but what do you expect when they are so cheap. So I taped them to a pole in the same office next to the thermostat. I was there for 3.5 hours and they are still showing around 40 degrees. You may be wondering why this madman would buy two thermometers when the office has one. Well my office mate and I have different ideas of what comfort is and I was hoping the thermostat was wrong (reading 2-3 degrees warmer than I thought). I know there are worse problems in the world.