Infrared thermometers measure heat that is emitted as infrared light which is invisible to the naked eye. The lightweight portable units are widely used in the food and science industry for fast surface temperature readings. Models of infrared thermometers vary in their viable measurement range, proper method of use and after market calibration. Use your infrared thermometer according to the manufacturers suggestions to measure the temperature of water quickly and correctly.
Read the instructional manual for the particular model of infrared thermometer to understand the proper distance to achieve the most accurate temperature measurements.
Place a strip of masking tape down the side of an empty clean aluminum beverage can.
Pour the water into the aluminum beverage can. A funnel can be helpful if you are pouring from a large pot or vessel.
Hold the infrared thermometer perpendicular to the masking tape strip at the distance suggested in the instructional manual and activate the light beam by pressing the trigger.
Wait a couple seconds for the reading to appear on the screen then retest to verify the temperature.
Measuring clear liquids in reflective pots can lead to false readings due to reflected infrared light. Measuring foods through a cloud of steam will lead to incorrect temperature readings.