System stabilizacji warunków środowiskowych w Laboratorium Wzorców AC-DC

Odtwarzanie jednostek miar oraz przechowywanie i wykorzystywanie ich wzorców pierwotnych musi odbywać się w odpowiednich warunkach środowiskowych. W pracy przedstawiono opis systemu stabilizującego warunki środowiskowe w Laboratorium Wzorców AC-DC Instytutu Metrologii, Elektroniki i Automatyki Politechniki Śląskiej. W artykule zamieszczono również wyniki badań systemu oraz zaproponowano metody jego udoskonalenia.

Primary standards of physical quantities are the basis of traceability and uniformity of all measurements. Appropriate environmental conditions should be provided to maintain the standards and reproduce unit of measures. In the paper there are described the resources used for stabilization of temperature and humidity in the Laboratory of AC-DC Standards. The results of investigations of environmental parameters and possibilities for their further improvement are presented. A view of the interior of the electromagnetically shielded chamber and of the measuring station in the chamber of the Laboratory of AC-DC Standards are shown in Figs. 1 and 2, respectively. A measuring system consisting of an air handling unit suspended over the chamber and other devices cooperated with it (Fig. 3) ensures temperature and humidity stabilization inside the chamber. An air conditioning system based on the chilled water enables setting temperature in the range from 20 to 25°C. In order to confirm the assumed temperature stability (maximum ±0,2 K per hour), suitable measurements were taken with use of a thermohygrometer Label LB706B. The results of short and long-term stability of the temperature at the measuring station are shown in Figs. 4 and 5, respectively. Based on the presented results, it can e concluded that the system presented in the paper meets the assumed environmental requirements and enables realization of an AC-DC transfer with type A uncertainty at the level of V/V.