It has been my experience that the non-mercury thermometers we got to replace our mercury ones some years back are considerably less accurate than mercury thermometers. For example, we do a steam distillation of limonene/water from orange peels and when we switched we routinely got b.p.'s above 100 degrees. The true result is a bit under 100 degrees and that is a concept we are trying to get across. As another writer mentioned, digital is better. For routine use in our organic teaching labs we use a thermometer like the Thomas traceable lollipop shockproof/waterproof thermometer, 8" stem except that I don't think we get it from Thomas. You can find a picture on Amazon.com. Then we get much better numbers in distillations and m.p.'s. I just wish the stem was a bit thicker to fit in our thermometer adapters better but we make do with some o-rings for distillations and a copper sleeve insert in our MelTemps for better heat transfer.