There appears to be no widely used method of measuring the temperatures of liquid samples in ir spectroscopy, although Potts has suggested the use of a resistance thermometer. Other authors have used thermocouples, but common types of thermocouples will not fit into the sample spaces of ir liquid cells so that a nagging doubt remains about the actual temperature of the sample in the beam. In this investigation, temperatures inside the cell were determined with an accuracy of ± 0.1°C by means of a thermocouple made from two 0.0025 cm diam Platinel wires spot welded together.
Maurice Cormier and James L. Thompson, "Measurement of Aqueous Solution Temperatures in Infrared Spectroscopy," Appl. Spectrosc. 24, 465-466 (1970)