Temperature Measurement using Thermocouples

Temperature measurement using thermocouples white paper

A white paper on Temperature Measurement using Thermocouples (part 1) has been released by our friends at Acromag.

Background Information on Temperature Measurement

Did you know that temperature is the most measured parameter in industry?

Most industrial applications require that a temperature be measured remotely, and that this signal be transmitted some distance. An industrial transmitter is commonly used to amplify, isolate, and convert the low-level sensor signal to a high level signal suitable for monitoring or re transmission.

With transmitters, your choice of sensor type is generally limited to Thermocouple (T/C), or RTD. But given the wide variety of RTD and T/C types, how do you choose the best sensor type for your specific application?

This paper will look at important characteristics of these two main industrial sensor types and offer information to help you select the best type for your application. Part 1 explores the thermocouple (this paper) which leads onto Part 2 looks at the RTD. Part 3 compares thermocouples and RTD’s and gives information for choosing between them.

Topics of Part 1 Temperature Measurement using Thermocouples

  1. The basics of measurement using thermocouples
  2. Common Thermocouple types and their applications
  3. Points to consider when using Thermocouples to measure temperature

a. Thermocouple sensor inaccuracy

b. Thermocouple sensor non linearity

c. Sensitivity

d. Age, drift and de-calibration

e. Choice of Extension Wire

f. Response Time

g. Cool junction compensation

h. Connection Problems

i. Thermal Shunting and Immersion Error

j. Lead Resistance

k. Noise

l. Common Mode Voltage

m. Other points to note

About Acromag

Acromag is a leading manufacturer of temperature transmitters and signal conditioners for use with thermocouple and RTD sensors. These instruments convert the sensor input to a proportional 4-20mA DC current, DC voltage, Modbus, Profibus, or Ethernet signal to interface with a PC, PLC, DCS, or other control equipment.
Acromag has designed and manufactured measurement and control products for more than 50 years. They are an AS9100 and ISO 9001-certified international corporation with a world headquarters near Detroit, Michigan and a global network of sales representatives and distributors. Industries served include chemical processing, manufacturing, defence, energy, and water services.

Metromatics are proudly their distributor in Australia, contact us now to find out more.