how many reference points are needed to properly gauge temperature?

Answer by  Bobbin (19)

In order to gauge temperature, only two reference points are needed, in the Centigrade or Celsius scale two temperatures are set, 0 degrees at the freezing point and 100 degrees at the boiling point of water, giving 100 individual degrees, all other temperatures can be determined from this.

Answer by  step (309)

You really only need one reference point. But to be on the safe side I would calibrate my thermometer using the following data. Water boils at 100 degrees Celsius or 212 degrees Fahrenheit and water freezes at 0C, or 32F. You can extrapolate everything in between from these two readings.