Qualification of effluent treatment plant

Temperature measurements are readily made using commercially available instrumentation. Thermocouples of the copper-constantan (T) type are usually chosen as the measurement probes. These can be made sufficiently small to ensure point measurements can be taken. Thermocouple hot junctions less than 1 mm wide can be used to measure temperatures in small containers and crevices, regions likely to retain air in sterilisation processes or into which heat conduction or convection is inefficient. Kemper gives full details of the theory and applications of thermocouple devices. 

All instruments must be calibrated before use and be certified by some independent body. A calibration check on the complete measurement system, including probes, must be undertaken immediately prior to the qualification test. A standard temperature source or measurement device, traceable to an approved national standard such as the National Physical Laboratory (NPL UK) or National Bureau of Standards (NBS USA), is used. 

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