01/02/2022
Temperature Calibration
All thermometers need to be characterized or calibrated. In industry the need to calibrate is often very real and practical.
No thermometer will remain entirely constant, thermometer and sensors such a Mercury-in-glass (MIG), Thermocouples (T/C), Thermistors, Resistance Thermometers (RTD) change their characteristics with time, temperature cycling and they can become contaminated.
There is a need to calibrate to meet Quality Standards, which for medical and safety applications may be vital to safeguard life. Calibration can improve efficiency, often if a thermometer’s characteristics are known more accurately savings in cost can be made. The requirement to calibrate temperature sensors continues to grow.
Isothermal Technology has focused on providing calibration solutions for the calibration of all types of thermometers.
The Three Levels of Temperature Calibration
Primary Laboratories
Primary Labs are often National Laboratories, now known as National Metrology Institutes, NMIs.
Secondary Laboratories
The secondary laboratory is so called because it does not maintain “Primary Standards”. These labs generally calibrate thermometers against standards in comparison baths.
Industrial Calibration
Temperature indicators are often calibrated with electrical simulators which are connected to the instruments sensor input. The device can then be rapidly checked by programming the equivalent “temperature” input into the indicator.
However the temperature sensor will have the potential for larger drift so it is very important to test and calibrate the temperature sensor with a heat source.
Types of Equipment
There are a wide variety of heat sources for industrial calibration the most popular type is the Dry Block Calibrator. Available in temperature ranges from 65°C below ambient up to 1200°C.
More recently multi purpose sources and liquid baths have become increasingly popular.
The Isocal-6 range of products from Isotech is unique; it can be used in six different modes. As standard the units can be used as Dry Block Calibrators with a removable metal block drilled to accept temperature sensors. The block can be removed and replaced with a tank of liquid which is stirred as it is heated or cooled. Other accessories allow it to be used to calibrate surface sensors and infrared thermometers. The Isocal-6 can be considered as a portable calibration laboratory.
To help users involved in temperature calibration Isotech has launched a comprehensive E-learning program. This £3-million project has enabled Isotech, in partnership with the University of Liverpool and Connect Internet Solutions, to create high-quality courses incorporating multimedia features and on-line interactive assessment. The benefits of the course include increased understanding of temperature calibration, the methods of calibration, the types of equipment available, how to select the appropriate equipment, how to avoid common pitfalls.
Further information from: Lenton Laboratory & Scientific Equipment
238 Smit Street, Fairland, Randburg, 2030
P.O. Box 73437, Fairland, 2030.
Tel: +27 11 476 4662
Fax: +27 11 476 4664
Email: [email protected]
Lenton Laboratory & Scientific Equipment. Lab Supplies & Laboratory Equipment serving South Africa and throughout the African continent. A leading scientific equipment supplier since 1992.
