Can the 732 be calibrated? I just looked at the manual and saw no mention of that. It would be really cool if I could add or subtract an offset.
I too have observed, at room temperature, a 2-3 degree (F) difference between the two probes. The difference, at least with my unit, is entirely in the probe, so if you interchange the connections into the transmitter, the temperature readings also switch to the other side.
I have checked the probes using boiling water and an ice water bath, and they usually read within 1-2 degrees of where they should be.
BTW, if you are more than 1,000 feet above sea level, you need to read this chart (or any other chart) to adjust the boiling temperature reading you are looking for:
If you want even more precision that offered by this graph, and are major-league geek like me, you can use the following calculator which will give you the precise boiling temperature, including not only altitude, but also barometric pressure (you pilots know all about this):
Water Altitude Calculator
When doing the ice water test, you need to stir the water and ice, and keep doing that for at least a minute. It works better if you have an ice crusher, but that isn't absolutely necessary. If you are
really trying to be accurate, you should do both tests with distilled water, but this is probably only necessary for a true precision instrument, like the
Thermapen. Various minerals can change the temperature reading considerably. For instance, for those of you who have made ice cream the old-fashioned way, adding salt to the water/ice mixture allows the water to get to a lower temperature without freezing. Therefore, if your water is a little brackish, as it is in many wells near the ocean, your ice water bath is probably going to give you a reading lower than 32 degrees.
Sorry if this is too geeky, but forty years ago I worked at the test and measurement division of Hewlett-Packard and wrote papers on how various measurements could be traced back to the National Bureau of Standards, including all the accumulated errors along the way, so you could say: "this thermometer measures temperature in the range of 32 to 550 degrees, +/- 0.7 degrees, traceable to the NBS."
BTW, when I do these tests on my
Thermapen, it is dead-nuts on. 32.0 and 210.9 degrees (boiling temperature at my altitude). It is an amazing piece of equipment.