Recently I was contacted by a professor at a Wisconsin University. He is researching bumblebees and wanted to measure and record the temperature inside their nests. Due to the need for more accurate measurements we settled on T-type thermocouples and to minimize the impact from the insulation we used a teflon PFA insulated wire, which is very inert and will lot leach any chemicals. We made these thermocouples in a range of lengths, up to 5 meter (15 ft) long. Do you have a special measurement task? I am happy to help!