Comparison of Two (RTD) Temperature Sensor Probes
Functional comparison of wire-wound RTD sensor probes and thin-film RTD element probes (PT100, PT1000).
A temperature detector (RTD) is a temperature sensor, often called a resistance thermometer. Its working principle is based on changes in metal resistance caused by temperature changes. RTDs are used in a variety of applications and are superior to other types of temperature sensors due to their accuracy, ease of use, repeatability, and cost.
Temperature sensors are used in different household and industrial applications. Resistance thermometers are most commonly used for temperature measurements from -200C to 600C, with some sensors designed to operate at temperatures up to 1000C. Temperature detectors can use a variety of resistive element materials.
1. The two most widely used sensor types:
1. Wirewound RTD
This type of RTD has a small diameter wire, most commonly platinum wrapped in a coil placed within a ceramic/glass insulator. Extension wires are soldered to this platinum coil that extends to the outside of the insulator. Compared to thin film sensors, this type of sensor is longer and more delicate. Wirewound RTDs have good accuracy over a wider temperature range.
2. Thin film RTD components
Thin film components are made by depositing a very thin layer of resistive platinum metal on a ceramic substrate. This film is then coated with epoxy or glass, which helps protect the deposited film and also acts as a stress relief for the external leads. This type of RTD performs better in vibration applications and field temperature measurements.
Due to their versatility and cost-effectiveness, thin film sensors are the most widely used sensor type. RTDs can also be distinguished based on the resistive element material. They are usually called Pt100, P1000, Ni120, Cu100, etc. Here the letters indicate the material of the component and the numbers indicate the resistance value at zero degrees Celsius. So a Pt100 element has a platinum resistance element with a resistance of 100Ω at 0°C and a Ni120 has a nickel element with a resistance of 120Ω at 0°C.
2. Each material element has its own advantages and limitations:
Platinum is the most widely used element and has excellent corrosion resistance, long-term stability and a wider temperature range from -200°C to 1000°C. However, platinum is a Nobel metal and these sensors are more expensive compared to other sensors.
Nickel elements are cheaper compared to platinum elements, they have higher resistance at 0°C and provide higher sensitivity due to high resistance ratio. However, they have a limited temperature range of -80°C to 260°C and age faster.
Compared with other elements, copper has excellent temperature linear resistance and is a low-cost material. However, it has poor corrosion resistance and its use is limited to a temperature range of -200°C to 260°C.
A temperature detector (RTD) is a temperature sensor, often called a resistance thermometer. Its working principle is based on changes in metal resistance caused by temperature changes. RTDs are used in a variety of applications and are superior to other types of temperature sensors due to their accuracy, ease of use, repeatability, and cost.
Temperature sensors are used in different household and industrial applications. Resistance thermometers are most commonly used for temperature measurements from -200C to 600C, with some sensors designed to operate at temperatures up to 1000C. Temperature detectors can use a variety of resistive element materials.
1. The two most widely used sensor types:
1. Wirewound RTD
This type of RTD has a small diameter wire, most commonly platinum wrapped in a coil placed within a ceramic/glass insulator. Extension wires are soldered to this platinum coil that extends to the outside of the insulator. Compared to thin film sensors, this type of sensor is longer and more delicate. Wirewound RTDs have good accuracy over a wider temperature range.
2. Thin film RTD components
Thin film components are made by depositing a very thin layer of resistive platinum metal on a ceramic substrate. This film is then coated with epoxy or glass, which helps protect the deposited film and also acts as a stress relief for the external leads. This type of RTD performs better in vibration applications and field temperature measurements.
Due to their versatility and cost-effectiveness, thin film sensors are the most widely used sensor type. RTDs can also be distinguished based on the resistive element material. They are usually called Pt100, P1000, Ni120, Cu100, etc. Here the letters indicate the material of the component and the numbers indicate the resistance value at zero degrees Celsius. So a Pt100 element has a platinum resistance element with a resistance of 100Ω at 0°C and a Ni120 has a nickel element with a resistance of 120Ω at 0°C.
2. Each material element has its own advantages and limitations:
Platinum is the most widely used element and has excellent corrosion resistance, long-term stability and a wider temperature range from -200°C to 1000°C. However, platinum is a Nobel metal and these sensors are more expensive compared to other sensors.
Nickel elements are cheaper compared to platinum elements, they have higher resistance at 0°C and provide higher sensitivity due to high resistance ratio. However, they have a limited temperature range of -80°C to 260°C and age faster.
Compared with other elements, copper has excellent temperature linear resistance and is a low-cost material. However, it has poor corrosion resistance and its use is limited to a temperature range of -200°C to 260°C.
