Temperature Calibration in the Pharmaceutical Industry

The pharmaceutical industry manufactures products that directly affect the life of billions of people. A seemingly small mistake could adversely affect the health of thousands of consumers. Recognizing these stakes, various regulations have been implemented for the pharmaceutical industry to ensure the integrity of pharmaceutical processes and, hence, the safety and efficacy of pharmaceutical products.



Pharmaceutical processes, packaging and storage typically incorporate many temperature measurements to ensure product quality. Temperature calibration on a timely basis is an important aspect of ensuring that a pharmaceutical product is manufactured properly.



Temperature calibration can be carried out thermally, using probes or electrically, using instruments. It can be performed directly with certified equipment or indirectly with traceable standards. Temperature calibration is achieved by elevating (or depressing) the temperature sensor to a known, controlled temperature and measuring the corresponding change in its associated electrical parameter (voltage or resistance). The accurately measured parameter is compared with that of a certified reference probe and the absolute difference represents a calibration error. While this is a comparison process, absolute temperatures are provided by fixed-point apparatus.



In the pharmaceutical industry, there are temperature sensors such as RTD (resistance temperature detector) and thermocouples, which tell difference in temperature by converting it into electrical signal. RTD calibration is necessary for calibration of RTD transmitters, in units of °C or °F. RTD calibration is also widely used for thermocouples because the resistance that an electrical conductor such as a platinum element exhibits to the flow of an electric current is related to its temperature.



A thermocouple works on the principle that when two different metals are joined together, there is a potential difference at the point of contact that varies with changes in temperature. Thermocouple refers to the joining of two metals, while thermocouple calibration denotes the combination of metals, with different combinations utilized for different temperature measurements. Thermocouple calibration also refers to the method of testing the thermocouple for accuracy.



In any pharmaceutical setup, temperature calibration is performed to meet official regulations, to obtain traceability, to optimize quality and energy efficiency, to reduce wastage of raw materials, to achieve optimum machine performance and to reduce unexpected repairs. Temperature calibration is applied to several instruments. Some of them are precision RTD probes; chart recorders; data collectors; dial, glass, digital and infrared thermometers; infrared temperature sensors; psychrometers; temperature meters; temperature controllers; temperature indicators and temperature transmitters.