Partial Immersion or Total Immersion Thermometers?
How do partial and total immersion liquid-in-glass thermometers differ?
Liquid-in-glass thermometers can be used to measure atmospheric temperature, semi-solids, or liquids. The main difference between partial and total immersion thermometers is the application in which they should be used. If the depth of the test sample is shallow, a partial immersion thermometer is usually necessary.
Thermometers manufactured for total immersion indicate an accurate temperature reading when the thermometer is immersed to the level of the liquid in the capillary column. To begin, immerse the thermometer to the top of the liquid column as the temperature rises or falls adjust the thermometer until an accurate reading is achieved.
Thermometers manufactured for partial immersion indicate accurate temperatures when the thermometer is immersed to the specific depth indicated by the immersion line on the individual thermometer, and regardless of the of the liquid in the column. Partial immersion thermometers are appropriate for any application where total immersion is impractical or impossible, such as in a shallow water bath.
Can I use a total immersion thermometer in a partial immersion application or vice versa?
Yes, but it is not practical. If total immersion thermometers are used at partial immersion depths (or vice versa), inaccuracies will occur. These inaccuracies increase as the temperature increases above room temperature; temperature readings can vary 5 to 10 degrees. If, in a rare case, you must use a total immersion thermometer in a partial immersion application, corrections for emergent stem must be obtained to achieve an accurate reading. To reduce errors, use the correct thermometer to meet your application requirements.