Abstract: Loop resistance is measured in a live-earth conductor loop comprising a residual current device powered by an alternating current mains supply. A measurement circuit having a low-pass filter characteristic arranged to substantially remove signal components at the frequency of the alternating current mains supply is used to measure, in a first period, a voltage across live and earth conductors of the live-earth conductor loop to determine a first voltage. A current application circuit is used to apply a unipolar test current having a magnitude below a trip current value of the residual current device for a second period and the measurement circuit is used to measure a second voltage between the live and earth conductors. Based on a difference in test current between the first and second periods and a difference in voltage between the first voltage and the second voltage, the resistance of the live-earth conductor loop is calculated.

Abstract: An electrical plug for testing an electrical mains socket is provided. The plug comprises a pin for engagement with a pin receptor of the mains socket. The pin comprises first and second electrical contacts, each comprising a surface portion to engage with a different respective region of the receptor. The first and second contacts are electrically isolated from one another at the pin. An electrical testing system and a method of testing an electrical mains socket is provided. The testing system comprises the electrical plug and a first circuit connected to the contacts and configured to measure an electrical resistance therebetween. The method includes providing the electrical plug and measuring an electrical resistance between the electrical contacts. A further method is provided for testing an electrical mains plug comprising a pin, by providing an electrical socket with a pin receptor having first and second regions electrically isolated from one another.

Abstract: Test apparatus is provided for testing an electrical property of a fluid. The apparatus comprises an electrically conductive container (1) forming an outer electrode of a test cell for containing the fluid, an inner electrode (2) of the test cell, an inductive heating assembly (3) and a cooling means. The inner electrode (2) of the test cell is arranged, when mounted relative to the electrically conductive container (1), to project into, and remain electrically isolated from, the electrically conductive container (1). The inductive heating assembly (3) comprises an inductive heating coil (4), which surrounds the electrically conductive container (1), for heating the electrically conductive container (1) and the inner electrode (2). The cooling means comprises an air channel (9) to allow passage of air across a surface of the electrically conductive container (1), for cooling of the electrically conductive container (1).

Abstract: A clamp for establishing an electrical connection with a conductor is provided. The clamp comprises a first body and a second body. The second body is pivotally coupled to the first body. The first and second bodies define a receiving region therebetween for receiving a conductor. The first and second bodies are biased towards each other at the receiving region to clamp a conductor. The clamp also comprises a shutter, movably coupled to one of the first body and the second body. The shutter is biased into a restricting position in which entry into the receiving region is restricted.