P2.6 - Platinum Resistance Thermometer with Metrological Self-Check
- SENSOR+TEST Conferences 2011
2011-06-07 - 2011-06-09
- Proceedings SENSOR 2011
- P2 - Calibration, Maintenance, Monitoring
- Y. Baksheeva, K. Sapozhnikava, R. Taymanov - All-Russia D.I. Mendeleyey Scientific and Research, St. Petersburg (Russia)
- 708 - 713
In industry and transport, the automation of equipment is accompanied by the significant increase in the number of sensors built in this equipment. Traditional methods of periodical calibration become inefficient. A need to provide the reliable operation of automated equipment poses the problem of automatic checking the measurement information reliability.
An analogy between the ways of development of technical and biological systems proves that the most promising solution of the problem indicated is the metrological selfcheck of measuring instruments, in the first place, sensors embedded in the equipment.
In the paper, the procedure for developing a sensor with metrological self- checking is shown by the example of a platinum resistance thermometer (PRT). The procedure includes the following metrological investigations:
- analysis of potential sources of uncertainty;
- ranking of uncertainty components, which originate in the process of sensor operation;
- detection of critical uncertainty components;
- analysis of the availability of redundant measurement information in the sensor.
On the basis of these investigations, a sensor structure with redundancy, which is necessary to provide the metrological self-check, is being developed.
To develop a PRT with the metrological self-check, the authors suggest that a sensitive element (SE) should consist of the parts of different sensitivity with regard to influencing factors.
The efficiency of the method suggested is validated by results of the theoretical analysis and experimentally confirmed by the example of the PRTs with a SE of the “strain free design”.
Results obtained in calculation of the optimal parameters of a SE design are given. It is also shown that the choice of the method of the metrological self-check depends on a measurement range.
The sensors developed enable to carry out checks of their metrological serviceability and correction of measurement results directly in the process of operation. The authors believe that the solution proposed permits to increase the calibration interval by no less than 3 – 5 times.