In my labs we use hot plates with a 0-10 temperature knob. The hot plates don't have a temperature monitor, so i have no idea how hot each number can increase it or how hot it is at the time. Sometimes i have labs where i have to heat something to more specific temperatures or else the reaction will change or it will boil over. My only option right now is to use a thermometer which isn't always practical, and still its easy to mess up. Is there a general rule with hot plates and the heat knob numbers? I know there might be factors like, room temperature. But i'm not doing anything that requires super precision, so i only really need a decent estimate. The only thing i know is the temperatures are 25°C at "1" and 550°C at "10" We use these http://www.sigmaaldrich.com/catalog/product/aldrich/cls6795220?lang=en®ion=US Only thing i could think of is heating water and checking the temperature before heating anything important. But i wont have enough time for that. And my professor might say things like "watch it and don't let it boil too violently", but i just feel like theres just too much of a chance of messing up.