Resistance thermometers are an innovative form of temperature sensors that monitor thermal energy as a function of electrical resistance. This requires a pure metal element, typically copper (Cu) or platinum (Pt), with a proportional and accurate relationship between electrical resistance and temperature.

Generally, resistance thermometers act much like a standard thermocouple: they acquire thermal energy from a process environment and communicate the signal to a transmitter. This information can be viewed directly in the field with a head-mount display, or it can be accessed downstream using additional interfaces. The primary difference is that resistance thermometers exploit the repeatable resistance against temperature relationship of the metallic elements to measure temperature variations. Copper and platinum exhibit strong linearity when it comes to this relative change in resistance. Resistance thermometers can subsequently be used to measure changes in temperature across a broad range with excellent degrees of accuracy.

Multi-resistance thermometers operate on the same principle except with multiple wiring materials. A stainless steel, or nylon, sheath houses several metallic elements of different materials and lengths. These span the full length of the sheath, which is designed to mitigate potentially harmful environmental and mechanical factors that could cause the wiring to undergo dimensional changes.

One of the primary applications of multi-resistance thermometers is in the averaging of process and container temperatures over a period of time. Each element can be calibrated for high, low, and mid-point temperatures for extended accuracy across broad temperature ranges. Although there is an extensive range of suitable application areas for the technology, it has proven essential in custody transfer metering systems and tank monitoring for the storage of fluidic hydrocarbons.

MRT Products from TT Electronics

TT Electronics boasts unmatched expertise in the field of process monitoring and advanced electronics for industrial applications. We offer the DS2101 series of multi-resistance thermometers for true temperature averaging in demanding areas of application. The durable, sag-free housing is suitable for harsh and corrosive environments and has been certified to conform to the ATEX directive and EN50014 standards. Copper and platinum elements within the extremely stable sheath feature an electrical resistance of 100 ohms at either 0°C or 25°C (77°F).

The DS2101 is compatible with various industry-standard level gauges, ensuring optimal system integration and improved process monitoring from installation onwards.

Source：https://www.ttelectronics.com