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Seldom does one see such a perfect marriage, Chauvin Arnoux (www.chauvin-arnoux.co.uk) are renowned for their excellent clamps, and in fact there are very few instruments that appear to use anything but a Chauvin Arnoux clamp when called upon to measure current (and Fluke's standard 500A clamp that comes with the 43B is no exception!). Specifically the Chauvin Arnoux C-173 current clamp has the highest level of flexibility I have ever seen. Not only can it do the typical 1000A for 1V output that is common with this size of clamp, it can switch right down to 1A for 1V and has a low end metering range of just 1mA. All this with an inner jaw diameter of >50mm. That's right! A clamp suitable for measuring ground leakage currents from 1mA up. This makes 20mA, 30mA, and 100mA RCD nuisance tripping cases a breeze especially as the jaw will fit around all the wires (in most cases).
And, what's more, this clamp compliments the Fluke 43B perfectly as the settings on the clamp exactly match the input sensitivities of the 43B. But here's the impressive part about the impressive low range; Although their specification does not guarantee the phase shift at the low end, I have tested this to be better than 2°. This means, when coupled to the 43B, leakage can be verified to be purely capacitive i.e. non wasteful. I would strongly recommend drop testing be avoided and that the jaws be kept spotless. This done to maintain this accuracy. Lest we forget the other ranges; 10A is suitable for lamp circuits and light domestic loads, 100A is light to heavy domestic and light industry, and the full range1000A is suitable for small to medium enterprise. It is available in all common flavours being lead with 4mm plugs, lead with BNC, or built-in 4mm shrouded sockets. The choice, naturally, should be the BNC cable as this will fit the 43B with the BNC adapter inserted in Channel B. One clamp + one meter = nearly all jobs. Could not ask for more!
Note: This web page does not form part of any official documentation. © M.T.P. - 22.06.03 |
