Thermometers are essential for taking temperatures in the lab. These thermometers have a yellow backing to make graduations easier to read. This thermometer is total immersion and has a range of -20 to 110 deg C. Thermometers are essential for taking temperatures in the lab. These thermometers have a yellow backing to make graduations easier to read. This thermometer is total immersion and has a range of -20 to 110 deg C.