Testing and Measuring Equipment



Temperature Transmitter


Temperature Transmitter

Temperature transmittersare used in industrial manufacturing as a means of process control because they can provide feedback regarding temperature during different stages in the manufacturing process. In order to do this, a temperature transmitter picks up a signal generated by a temperature sensor, such as a thermocouple, and then uses the signal to calculate heat levels. Next, the data regarding temperature is converted into a different kind of signal and transmitted to a corresponding receiving device.
There are several different kinds of temperature transmitters as well as several types of mounting set-ups. The three general categories for temperature transmitters include explosion-proof and weather-proof transmitters, DIN rail or panel mount transmitters, and head mount transmitters. The three general kinds of mounting set-ups include rail mounting, field mounting, and head mounting. Some types of transmitters are named after the mounting method, meaning there is some overlap between the type and mounting method.

Table of Contents

-Weather-Proof and Explosion-Proof Transmitters

-Panel Mount or DIN Rail Mount Transmitters

-Head Mount Transmitters

-Field Mounting Transmitters

Weather-Proof and Explosion-Proof Transmitters

In applications where a transmitter must withstand the wear and tear associated with continuous exposure to the elements, a weather- and explosion-proof transmitter is appropriate. This particular type of transmitter has an external enclosure, usually made of stainless steel or a designated explosion-proof material, which is sealed tightly to protect the sensitive internal components. Inside, the transmitter is divided into two small chambers: one contains the sensor and the other contains the electronics associated with calculating temperature and transmitting a new signal. Weather-proof and explosion-proof transmitters tend to have a high level of accuracy, and can usually be adjusted and monitored locally, if needed.

Panel Mount or DIN Rail Mount Transmitters

A DIN rail is used to mount switches, relays, and transmitters. The rail itself is a piece of metal that is shaped to enable a device (such as a transmitter) to be attached using a spring clip, which slides into a bend in the metal rail and secures itself. The metal rail, complete with attached transmitter, can then be attached to a panel or a wall. The acronym DIN stands forDeutsches Institut fur Normung, which is the German Institute for Standardization. DIN rail transmitters, also called panel mount transmitters, are usually found in diverse applications because they are relatively low-cost and can operate with an array of different sensors. Because of the DIN rail configuration, they are also easy to install. They are somewhat less accurate than weather- and explosion-proof transmitters because of the longer wiring configuration necessary for securing the transmitter. For temperature transmitters, rail mounting is the oldest mounting method.

Head Mount Transmitters

Head mount transmitters incorporate the transmitter into the connection head, or exterior housing, of a sensor. Because of this design, they are easy to install and require minimal wiring, as the sensor head simply becomes a sensor head transmitter.

Field Mounting Transmitters

This particular kind of temperature transmitter comes installed in its own exterior housing, which enables it to be used "in the field” where conditions may call for extra protection, such as in high performance industrial operations. Field mounted transmitters can be located relatively close to the sensor to increase the strength of the signal.