Series 800 Loggers
Series 800 Loggers
TQSoft™ together with the Series 800 Data Logger provides a 21CFR Part 11 compliant system purpose designed for pharmaceutical thermal validation with thermocouples and pressure transducers.
The Series 800 TVI differs from the majority of data loggers by the design of the thermocouple input connection, associated thermocouple cold junction compensation and in the use of analogue input parallel processing enabling both units to have a scan rate of better than once per second for all inputs. The Series 800 TVI uses individual high speed amplification and analogue to digital conversion on each input channel with conversion to engineering units (°C/°F) carried out by the microprocessor in the Series 800. Data is communicated to the computer in the correct engineering units enabling the system to have a traceable calibration certificate. The Series 800 TVI has an internal power supply to provide a 20VDC excitation voltage for the 4-20mA inputs and no separate power supply is required for a powered transducer.
In the Series 800 TVI all cold junction compensation errors are minimized by using correctly compensated miniature type T thermocouple connectors with matching class 1 thermocouple wiring to the internal cold junction sensor. A 1/3 DIN Pt100 sensor measures the cold junction temperature to an accuracy of ±0.1°C at 0°C. Design of the physical layout of the cold junction reduces any thermal scatter to a typical deviation of ±0.05°C.
The Series 800 measurement range for type T thermocouples is -200°C to 300°C with a resolution of 0.01°C. Over a measurement range from -50°C to 300°C the overall system accuracy is ±0.25°C. This accuracy is maintained over an ambient operating temperature range from 0°C to 50°C and includes all errors due to thermocouple cold junction compensation, DC amplification, A/D conversion and thermocouple linearization.
The Series 800 TVI accuracy of ±0.25°C is a worst case "out of the box" value including all system errors but excluding thermocouple sensor error.
Series 800 TVI Measurement Uncertainty
Calibration of the complete measurement system of thermocouples, data logger and software against a UKAS reference thermometer each time the equipment is used reduces all errors, systematic and random, at the moment of calibration. Any measurements subsequently made with the complete measurement system have to be qualified by a statement of measurement uncertainty.
EN554, EN285, HTM2010 and HTM2030 (Scotland) require that the repeatability of measurement should be ±0.25°C or better and that the combined uncertainties of the complete measurement system, including sensors, should not exceed ±0.5°C. The measurement uncertainty is calculated using a statistical approach giving a final value at a 95% confidence level with a Gaussian distribution. Measurement uncertainty is a function of the equipment specification and characteristics and cannot be changed by any subsequent calibration.