STABILITÀ DI UN MULTIMETRO DI ELEVATA ACCURATEZZA DI RECENTE PRODUZIONE MEDIANTE CONFRONTO CON IL SISTEMA DI RIFERIMENTO DEL LABORATORIO DI TARATURA DI STRUMENTI ELETTRICI MULTIFUNZIONE DELL‘INRIM

In this technical report describes the work made in the laboratory of calibration of electrical multifunction automatic instruments of the National Institute of Metrological Research (INRIM) concerning the periodic metrological verification of a high accuracy multimeter commercial recently appeared on the market in order to assess its 'accuracy and stability compared with the manufacturers specifications. The instrument was tested in a seven months period inthe five basic electrical low frequency fundamental quantities (dc and ac voltage and current and dc resistance). Its stability was compared with its accuracy manufacturer specifications at 180 days. Some critical points where the instrument does not meet the declared specification have been identified.