Abstract: A measuring instrument with active and/or passive sensors, and a connecting device enabling one to associate any one of the sensors with the measuring instrument. The connecting device enables one to identify the sensor and to activate at least one function for protection of the user of the measuring instrument determined according to characteristics of the sensor connected. For this purpose, a multi-point connector allowing identification of the sensor chosen, activation of the protection, and establishment of a direct link for transmission of measurement signals from the sensor to the measuring instrument.

Abstract: An arrangement for measuring alternating or direct current based on the magnetic field generated by the flow of the current includes a sensor for sensing the magnetic field generated by the flow of the current, a measuring circuit for determining the current from the magnetic field, and a device for sensing an external parasitic magnetic field and producing a correction signal applied to the measuring circuit for accurate measurement of the current.