Total Immersion, Single Scale Range -20/150 degrees C, Scale: 1 Degree, 300mm Length Partial immersion is best for most applications. These thermometers are calibrated to read correctly when only 3" of the stem is immersed in the liquid being measured. Total immersion thermometers are calibrated for use when the entire liquid column is totally immersed in the substance being measured and should be used under those circumstances. All of our thermometers are made to SAMA specifications for ranges and accuracy. In addition, each of our thermometers has a number of extra quality features built into each one: REINFORCED BULBS, to prevent breakage, RING TOPS, for submersion, NON ROLL CAPS, SCALES PRINTED INTO THE GLASS, rather than on the surface so they never wear off.