Calibration Laboratory

Calibration of Temperature Measuring Instruments

Calibrating temperature measuring instruments is a crucial process that ensures the accuracy and reliability of measurements. Comeco Laboratory, accredited under ISO 17025, provides professional calibration services for thermometers and temperature sensors across a wide range of -20 °C to +1000 °C.

With precise reference equipment, including thermometers, liquid temperature baths, dry temperature blocks, and climatic chambers, Comeco guarantees high accuracy and resilience throughout the calibration process.

The calibration is carried out by a team of specialists with extensive experience, adhering to all internationally accepted standards and procedures. This ensures not only accurate results but also full compliance with industry and regulatory requirements.

If you require calibration of thermometers or temperature sensors, Comeco is your reliable partner.

Scope of Accreditation

• glass-liquid thermometers
  -20 °C…400 °С

• resistance thermometers
  -20 °C…1000 °С

• radiation (infrared) thermometers
  -20 °C…1000 °С

• contact thermometers for surface temperature
  -20 °C…1000 °С

• resistor temperature transducers
  -20 °C…1000 °С

• thermoelectric transducers
  -20 °C…1000 °С

• secondary temperature transducers and calibrators
  -200 °C…2500 °С

What is Temperature Calibration?

Temperature calibration is the process of verifying and adjusting the accuracy of temperature measurements made by thermometers or temperature sensors. It is particularly significant in industrial, scientific, and medical applications, where precise temperature measurement is critical for quality and safety.

Key steps in temperature calibration:

1. Identifying the Type of Thermometer
   The first step is to determine the type of thermometer or sensor being calibrated. Common types include platinum resistance thermometers (PRTs or Pt-100), thermistors, and thermocouples.
2. Preparing the Calibrator
   Calibration is performed using a controlled temperature source, known as a calibrator or reference instrument. This source provides a stable, precisely controlled temperature.
3. Comparison with a Reference Thermometer
   Measurements from the calibrated thermometer are compared against those of a “reference thermometer” with known accuracy. This is done across the temperature range the thermometer is designed for.
4. Adjusting Readings
   If the difference between the readings of the calibrated and reference thermometers exceeds acceptable limits, adjustments are made. Otherwise, the thermometer may be deemed inaccurate and require repair or replacement.
5. Documentation and Traceability
   A detailed report is prepared after calibration, describing the process, measurements, and any corrections made. This documentation is essential for traceability, particularly in industrial and laboratory settings.

Key aspects of the calibration process:

• Determining Actual Values
  Calibration involves measuring the actual temperature of the environment, expressed in Kelvin (K) or Celsius (°C), and comparing it to the instrument’s readings.
• Comparative Method
  Calibration is performed using a comparative method with a reference thermometer, ensuring precise and traceable results.
• Environmental Conditions
  Calibration requires specific environmental conditions, such as a temperature range of 18°C to 28°C and relative humidity between 25% and 75%.
• Measuring Electrical Quantities
  For resistance and electric thermotransducers, the actual values of electrical resistance or electromotive force are determined for the corresponding temperatures.
• Traceability
  It is essential to ensure traceability, meaning that reference instruments and methods used must have certified accuracy and reliability.
• Safety Considerations
  Adherence to safety standards is critical, particularly when working with electrical equipment and high temperatures.

Why Should Thermometers Be Calibrated?

Calibrating thermometers is essential for maintaining the accuracy and reliability of temperature measurements, especially in critical applications where precision is vital, such as quality control, scientific research, and medical diagnostics.

Reasons for calibration:

• Material Changes
  Over time, materials in thermometers can degrade. For example, bimetallic components may alter their structure, and thermocouple wires may corrode or suffer mechanical damage, causing inaccuracies.
• Environmental Factors
  Temperature, humidity, and other environmental conditions can affect the performance of thermometers. For instance, high temperatures can degrade certain materials, leading to measurement deviations.
• Wear and Mechanical Damage
  Temperature-measuring devices may experience physical stress or damage during operation, impacting their functionality and accuracy.
• Aging Processes
  Prolonged use of thermometers leads to material aging, which can alter their temperature characteristics and necessitate recalibration.
• Compliance with Standards
  Many industries and scientific fields require strict adherence to quality and measurement standards. Calibration ensures compliance with these standards.
• Critical Applications
  In fields like medicine, pharmaceuticals, and the food industry, precise temperature measurements are vital for safety and efficiency. Calibration ensures reliable and safe measurements.

Periodic calibration not only maintains measurement accuracy but also extends the lifespan of thermometers and enhances the overall quality of processes.