Extension wires, if used, must be of the same materials as the thermocouple wires. Thermocouples designed with their measuring junctions in contact with metal surfaces are known as grounded junction thermocouples. These are the most common, generally have the fastest response times, and are the most economical. Ungrounded junction thermocouples offer the advantage of electdcal isolation. Dwyer manufactures both types of thermocouples.
Thermocouples are generally more rugged and less expensive than other sensor types.
All Dwyer thermocouples are manufactured using industry standard alloys and meet stringent ANSI standards. This assures interchangeability with other standard thermocouples without special instrument recalibration. Dwyer thermocouples are used in all types of applications, can measure wide temperature ranges, and are offered in a large variety of standard configurations. RTDs RTDs are usually platinum wire wound on a glass or ceramic bobbin and sealed with a coating of ceramic or glass. They can also be made by depositing platinum as a film on a substrate and then encapsulating it.