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The clamp-on earth resistance tester is designed to carry out measurements on installations with parallel polyphase earthing, without having to disconnect the earth being tested. The procedure is carried out simply by clamping the earth conductor, or the earthing rod itself. The clamp jaws themselves open up to a full clamping diameter of 32 mm on these three models. Measurement is thus carried out quickly and with the minimum of fuss, even in difficult environmental conditions. The real strong point of these new clamps is their impressively wide measurement range, which extends from 0.1 Ω right up to 1.2 kΩ, so you can find the best earth with the least resistance. Because this method of measurement is carried out directly on the installation and doesn't involve disconnecting the earthing rod or other time-consuming procedures (loosening rusty bolts etc ...), it gives a highly accurate representation of the real earthing situation. Any decisions that are consequently made can be confidently based on reliable and accurate assessment. As well as measuring earth resistance, this measurement technique also makes it possible to check over the continuity of the connections and links to the earth (defective welds, conductive oxides, | loose nuts,...), which is all useful information to have when carrying out maintenance. Current measurement function Models C.A 6412 and C.A 6415 integrate a current meter function. The current probe is highly sensitive, able to measure leakage currents flowing to the earth (or in earth loops), from 1 mA up to 30 App. The extra data given by these measurements is highly useful, especially if the earthing networks is suffering from high noise or harmonic 'pollution' that has a knock on effect on the power supply quality. The battery level is indicated every time the clamp is switched on so as to prevent the user from being caught out whilst on site. There is also an automatic switch-off function if no button is pressed for over five minutes. This function can be deactivated if the user so desires. "Alarm" and "memory" functions The top of the range CA 6415 model | comes with these two advanced functions. In ALARM mode, a threshold value can be entered which triggers an audible or visual alarm if exceeded (the audible beep signal can be deactivated). The user chooses the triggering mode best suited to his or her application, either by setting a higher value (for a resistance value that is thought to be too high), or a lower value (for the continuity test). The alarm is particularly useful when conducting an On-Off test. In MEMORY mode, 99 values (resistance or current) can be | recorded. This function allows the user to carry out a series of measurements and then analyse the saved results later on. The alarm threshold value and those values recorded in the memory are stored, even after the instrument has been switched off. This data will only be wiped if the user wants to clear the memory. | |||||||
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