How do i calculate the percentage error of a themometer?
The only way that you can check the % error of a thermometer is to read what the thermometer gives as the temperature of a solution, the temperature of which is accurately known. A typical example would be to check the boiling point of distilled water. This must be 100.0°C at an atmospheric pressure of 101.3kPa. If your thermometer gives a temperature of 99.3°C, then obviously the percentage error at 100.0°C is 0.7% For your thermometer which reads a much lower range you obviously need another liquid. I am sure that you can obtain standard certified liquids with a guaranteed known boiling point in the range that you want. These should be obtainable from your laboratory equipment supplier, but probably at some ridiculous price. Once again say you get a liquid with a guaranteed BP of 45.0°C. Your thermometer reads 44.7°C , a difference of 0.3° in 45°, or 0.3/45.0*100 = 0.667% error While typing this up, the thought came to mind that if the measurement of temperature is critical, you can
