I've set up a temperature measurement rig for a project measuring the temperature of various indoor and outdoor temperatures, for a building physics investigation, and I'm getting some strange errors. The system works fine in the lab, and seemingly fine at one site, but at another site it's giving errors.
Most days, between about 12:30 and 13:30, the readings go silly for half an hour to an hour. The temperatures are around 15 to 20 C, but for the stated time, one thermocouple is reading around 30, while another is reading around -5 to -10 C. There's simply no way that the building in question is really that temperature. Could there be some sort of interference taking place? At the moment, I don't have a spare data logger to test, but it does work fine in other locations. It's a Campbell Scientific CR1000, with K type thermocouples. Other thermocouples connected to the same data logger work (seemingly) fine, even at that site, and the whole system seems to work at other sites - both before and after the strange measurements.
Suggestions very welcome!