Can the clamp type ground clamp clamp the flat iron directly in front?
Due to the special clamp resistance table structure, so that it can be easily used as a current meter, a lot of this kind of instrument, and has the function of clamp ammeters. On the other hand, the use of a certain frequency signal while the pincer ground resistance meter test to eliminate interference, but the measured cable has great current presence of measurement will be interfered, leading to inaccurate results. Therefore, in accordance with the requirements of the use of the cable should be measured on the current, only when the current is not very large, you can further measure the ground resistance. Some instruments automatically detect noise interference when measuring ground resistance and give hints when interference is too large to measure.
A ground resistance meter measuring principle of grounding resistance tester forcipated ground resistance meter is a kind of new measuring tools, it is convenient and fast, resembling the clamp meter, the test does not need auxiliary test pile, only to be a geodesic clip, a few seconds to get the measurement results, great convenience to resistance measurement. A ground resistance meter is also a big advantage is to measure the resistance of equipment in use, and do not need to cut off the power supply equipment or broken wire.
A resistance table ring which is a special electromagnetic converter into the cable through the front end card is AC constant voltage 1.7kHz, the current detection circuit, after filtering, amplification, A / D conversion, only the current generated by the 1.7kHz voltage is detected. Because of this, a ground resistance meter out of small current grounding commercial AC and high frequency noise caused by the device itself, in order to obtain accurate measurements, but also because of this, a ground resistance meter has the advantages of online measurement. In fact, the meter measures the impedance of the whole loop, not the resistance, but, in general, they are very small. A ground resistance meter immediately will be displayed in the LCD display, when no bayonet card, it can display the "open jaw" or similar sign on LCD.
E and I in the circuit by the said ring ring bayonet clamp resistance table, Rx is the geodesic pile resistance, R1, R2... Rn for distributed grounding system in ground resistance. The graph can be further equivalent to Fig. 3. When measuring, a ground resistance meter based on the principle of electromagnetic induction through the front bayonet (with a ring of electromagnetic coil) to the measured cable into a constant voltage E, the voltage is applied in the circuit shown in Figure 3, ground resistance meter can simultaneously through the front end of the loop current I bayonet measure. According to E and I, you can calculate the total resistance in the circuit
