The 1523 and 1524 Reference Thermometers measure, graph, and record PRTs, thermocouples, and thermistors. The instruments utilise current reversal technique to eliminate thermal EMFs for precision temperature measurements. Specifications are guaranteed from -10°C to 60°C ambient. The 1523 is a single-channel thermometer, while the 1524 has two channels, a real time clock, and memory for 15,000 time and data stamped measurements. Both feature a 128 x 64 backlit LCD display, and can document up to 25 readings and associated statistics.