What is an RTD, and how does it work?

Thermocouples – Electric Motor Parts & Accessories Australia​

A resistance temperature detector is a temperature sensor, also known as an RTD or resistance thermometer. Conductors attach the sensing element to the measurement instrument. Insulation and a protective sheath make up an RTD.

The linear relationship between temperature and resistance make this type of temperature sensor accurate and repeatable. The type of metal used in RTD construction, plus the thermal insulation, can dictate the temperature range at which the RTD can be used. An RTD’s sensing feature is an electrical resistor that changes resistance value as temperature changes. The transition in resistance with temperature occurs predictably.

An RTD’s sensing feature is usually made up of a wire coil or a substrate with a platinum etched film. The electrical resistance can be measured from a distance away from the method or material being measured thanks to extension wires connected to the sensing element. The sensing factor is enclosed in a protective sheath (usually stainless steel). Platinum is the most used material.

There are two main approaches for RTD construction. The most popular process is to insert the RTD part and wires into a metal tube with a closed-end. The tube is filled with a vibration dampening and heat transfer medium, typically alumina powder. The open end is sealed with silicone, epoxy, or ceramic cement.

A mineral insulated metal is an alternative building tool.

A mineral insulated metal sheath (MIMS) cable is an alternative construction process. The RTD element is connected to nickel or copper wires that are insulated with Magnesium Oxide (MgO). This end is also electrically insulated with MgO and welded shut. Before sealing, extension wires are connected to the other end.

Vibration Sensor Offering

MEC’s extensive range of vibration testing technology have which are manufactured to the best quality. MEC products specialise in vibration testing, and the efforts of our experienced team ensure that MEC will find the right solution to fit the application.

Accelerometers

MEC provides a vast range of quality accelerometers, including all top entry, side exit configurations, including dual output and our popular triaxial models. Also Included in our catalogue are all our acceleration, submersible and temperature models. Contact us to discuss our range as well as the typical and potential applications.

Vibration Modular Systems

MEC provides an extensive scope of power supplies, signal conditioning modules, housings and converter cards. You can see our product page, as well as the typical applications.

Switch, Connection and Junction Enclosures

We also supply a complete range of low-cost switch, connection and junction enclosures available in mild or stainless steel and GRP. 

Vibration Meter Kits

Our Vibration Meter Kits are reliable and easy to use hand-held machine condition inspection instruments available on the market. They provide optimum vibration measurement, bearing status check facility and an alarm indication

Cables & Accessories

We also supply access to an extensive range of accelerometer cable assemblies as well as cable assemblies, accelerometer & system integrity checkers, magnets, custom made solutions, and mounting studs.

Vibration Sensors

Vibration sensors or accelerometers are quite often used in condition monitoring applications that require measurement of acceleration, vibration or shocks experienced by the equipment or object. This measure the acceleration in reference to Earth’s gravity. The sensing element of the vibration sensor is electromechanical in nature and behaves as a damped mass attached to a spring, consisting of mechanical sensing elements with mechanisms to transition the mechanical vibration into electrical output. The sensing parts of the commercial accelerometers are usually made up of piezoelectric or capacitive material.
Accelerometers are accessible in an extensive range of models; charge-type piezoelectric or Integrated Electronics Piezo-Electric accelerometers with a broad range of frequency response for universal condition monitoring applications or vibration monitoring, DC-response piezoresistive accelerometer for shock tests, automotive crash tests or blast testing, or very sensitive variable capacitance accelerometers for automotive NHV (Noise, harness, vibration) tests, seismic testing and motion measurement. Vibration sensors can also be mounted on a drone and used as components of the inertia driven navigation assembly.
MEC Australia offers a complete suite of vibration measurement sensors to support almost all industrial and research applications’ condition monitoring program and testing requirements. MEC accelerometers have been widely used in university research laboratories and industries such as defence and military, automotive, manufacturing, mining, aerospace, geotechnical, marine, and oil and gas. Examples of applications are Missiles and ballistic testing, aircraft flight test, seismic monitoring, automotive crash test, vibration monitoring in gas turbines and many others.