Resistance Thermometers (RTD and Pt100 Sensors)

Frequently Asked Questions

• What is a resistance thermometer, and how does it work?
  A resistance thermometer measures temperature by detecting changes in electrical resistance. The "Pt" stands for platinum, the material used in the sensing element, and "100" refers to the resistance value of 100 ohms at 0°C. As the temperature changes, the resistance of the platinum element varies, allowing for accurate temperature measurements.
• How accurate are Pt100 sensors?
  Pt100 sensors offer high accuracy and stability, with industrial-grade elements ranging from Class B (±0.3ºC at 0ºC) to Class A (±0.15ºC at 0ºC). Higher precision options, such as 1/10 class elements, provide an accuracy of ±0.03ºC at 0ºC. These sensors are widely used in industrial, laboratory, and scientific applications requiring high precision. Additionally, we offer calibration services in our UKAS accredited laboratory.
• What is the temperature range for resistance thermometers?
  The temperature range of an RTD sensor depends on factors such as the construction, sheath material and insulation used in the construction. While some platinum elements can withstand temperatures up to 850°C, the overall sensor design will limit the maximum temperature rating. Please check the product specifications for the exact temperature range based on the sensor’s construction. If you need any advice, our engineers are happy to assist!
• What is a resistance thermometer used for?
  Resistance thermometers are widely used for accurate temperature measurement in industrial, scientific, and commercial environments. Common applications include process control, laboratory testing, HVAC systems, and food and beverage production. Their precision and stability make them ideal for situations where consistent and repeatable readings are critical.
• Is a resistance thermometer the same as an RTD?
  Yes, a resistance thermometer is another term for an RTD, or Resistance Temperature Detector. The terms are often used interchangeably, although \"resistance thermometer\" is more common in formal or technical literature. RTDs typically use platinum elements (such as Pt100) to measure temperature through changes in electrical resistance.
• What types of resistance thermometers do you offer?
  We offer a wide range of resistance thermometers, including Pt100 and Pt1000 sensors in 2-wire, 3-wire, and 4-wire configurations. Options include surface sensors, immersion probes, ATEX-approved sensors for hazardous areas, and custom assemblies tailored to OEM or industrial applications. All are manufactured in the UK to ISO 9001 standards.
• How do I choose between a Pt100 and a Pt1000 resistance thermometer?
  Pt100 sensors have a resistance of 100 ohms at 0°C, while Pt1000 sensors have 1000 ohms at 0°C. Pt1000s are often preferred for longer cable runs because of their higher signal-to-noise ratio, whereas Pt100s are more widely used in industrial systems and instrumentation. The choice depends on the measurement environment and your system’s compatibility.
• Do resistance thermometers require calibration?
  Yes, for critical applications or compliance with quality standards, regular calibration of resistance thermometers is recommended. We offer calibration services through our UKAS-accredited laboratory to ensure traceability and measurement confidence. Certificates are available with each calibrated sensor upon request.