Difference Between RTD and Thermocouple (With Table)

The world today has changed enormously. It is changing at a great speed over time, and almost every field is growing rapidly. May it be science, arts, music, literature, technology, engineering, medical or architecture. Several inventions have been made of several devices, and that has helped human beings in their daily lives to carry out various tasks easily and hassle-free. Various discoveries have been made that have made things and concepts clearer to the people.

However, to measure temperature, there are certain instruments that are used. Mainly to measure body temperature, a thermometer is used, but there are other devices as well. Two of those devices are 1. RTD or Resistance Temperature Detector and 2. Thermocouple.

RTD vs Thermocouple

The difference between RTD and Thermocouple is the number of shifts and stability shown by each of the devices. The RTD or the Resistance Temperature Detector is more stable and shows lesser shifts. On the other hand, the thermocouple is less stable and has more shifts.

The RTD is a type of device that is used to measure temperature. It is made of a thin wire, most of the RTD’s are made of thin wire, but other types of RTD’s also use other materials. The RTD is the Resistance Temperature Detector. It is also addressed as Resistance Thermometer.

The thermocouple is a type of device or a sensor that is used for the measurement of temperature. Various processes that require measuring temperature make use of thermocouples to do so. They are produced by several companies in a variety of styles. These thermocouples vary from each other slightly.

Comparison Table Between RTD and Thermocouple

Parameters of ComparisonRTDThermocouple
Suitable temperatureIt is mostly suitable for the measurement of low temperatures. It is mostly suitable for the measurement of high temperatures.
AccuracyMoreLess
StabilityMoreLess
Number of shiftsLessMore
Form of outputLinearNone-linear

What is RTD?

The RTD is a type of device that is used to measure temperature. This temperature measuring device is available in different styles depending on the construction of the device. However, the main and basic structure of an RTD is quite simpler. It is very well known and most used for its advantages.

The RTD is a Resistance Temperature Detector or is also known as Resistance Temperature. During the construction of a resistance temperature detector, the utmost attention is given to the selection and design of the protective sheaths that are present in it. These sheaths play an important role in the overall working of the device.

These protective sheaths are called do because they make sure that during any chemical or physical hazard, the main device is protected and the convenient points for attachments are provided. These devices use electrical resistance for the overall operation of the device.

Because they use electrical resistance, they require a power supply for working. The wiring configurations are different in different detectors. There is a two-wire, three-wire or even four-wire configuration. The Resistance Temperature detector has certain limitations and advantages. The advantages include it provides low drift, wide range for an operation etc.

What is Thermocouple?

The thermocouple is a type of device or a sensor that is used for the measurement of temperature. The working of a thermocouple includes the joining of two wires that are made up of two different metals, and one of the wires is heated, and the current is passed through the thermoelectric circuit.

A thermocouple is a sensor, to be precise, that is used to measure temperature during various chemical and physical processes. They are produced by several companies in a variety of styles. These thermocouples vary from each other slightly. They have their independent advantages and disadvantages.

Different types of thermocouples include thermocouples with probes, thermocouples with probes and connectors, thermocouples with probes that have a transition joint, thermocouple that has a bare with, thermocouple that is only a wire etc. Depending on the necessity and use, people choose the thermocouple for various processes.

If made use of nicely and with great precautions, a thermocouple is a very effective sensor device, and it completes its purpose successfully. It also provides great advantages like it is cost-effective, it provides a measurement of wide ranges of temperature, it comes with a construction that is rugged, it does not require additional bridged circuits etc.

Main Differences Between RTD and Thermocouple

  1. A resistance temperature detector is slightly costly. On the other hand, the thermocouple is not costly.
  2. The output obtained by a resistance temperature detector is linear. On the other hand, the output obtained by a thermocouple is non-linear.
  3. The response time produced by a resistance temperature detector is good, but it is comparatively slower. On the other hand, the response time produced by a thermocouple is faster.
  4. The small fluctuations are recorded by a resistance temperature detector. On the other hand, the small fluctuations are not recorded by thermocouples.
  5. A resistance temperature detector is more sensitive. On the other hand, the thermocouple is less sensitive.
  6. A resistance temperature detector is more accurate. On the other hand, the thermocouple is less accurate.
  7. A resistance temperature detector is more suitable for the measurement of small ranges of temperature. On the other hand, the thermocouple is more suitable for the measurement of big ranges of temperature. And thermocouples are extremely important for the measurement of temperature during various physical and chemical processes.

Conclusion

Both resistance temperature detectors and thermocouples are extremely useful and helpful when it comes to measuring temperature during various physical and chemical processes.

They do have some shortcomings, but they are overcome by the advantages that they provide. They provide the accuracy and stability that is required during a certain process.

Inventions like these help human beings in many ways. They make a certain task easier, and they also provide accuracy. Because they provide accuracy, the chances that an error might occur are extremely low.

References

  1. https://www.tandfonline.com/doi/abs/10.1080/09654319808720451
  2. https://www.osti.gov/biblio/20002672
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