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Flexible AC current probes measure up to 2000A

02 November 2010 - GMC-I PROSyS has extended its range of non-invasive current measurement probes with the MICRO-flex ACP 2005 and the ACP 2015, providing a convenient, flexible and accurate means of measuring AC currents from 200 mA to 2000A, with no requirement for disconnecting or breaking into primary circuits.

The MICRO-flex ACP 2005 measures AC current in three switched ranges, with full-scale values of 20, 200, and 2000A, making the unit ideal for monitoring currents in Power Quality and Energy management applications and in any mains-powered device, electric motor, or uninterruptible power supply. It provides an output, in each range, of 0 – 2.0V full scale, simplifying connection to any digital multimeter, oscilloscope or chart recorder. The probe features accuracy of ± 1% of reading.

The MICRO-flex ACP 2005 measure AC current using the Rogowski coil principle. Integrating the signal from the coil yields an output that accurately represents the primary current. The design of the MICRO-flex allows measurements to be made in confined spaces that afford only limited access. In the ACP 2005 the detection coil takes the form of a thin, 6 mm diameter, flexible assembly; the user opens the loop, passes it around the primary conductor and re-connects it to the probe head. An advanced coupling design ensures consistent closure of the loop, and totally repeatable results.

A Rogowski coil is air-cored and free from saturation and circuit-loading problems: the principle is noted for its linearity and accuracy. In the ACP 2005 measurement error due to off-centre conductor positioning within the magnetic loop is only ± 2% of reading: linearity across the range is within ± 0.2% of reading. Three model variants, with differing magnetic loop lengths, cater for primary current conductor diameters of 50, 70 and 100 mm. Frequency response of the ACP 2005 is from 20 Hz to 100 kHz. The ACP 2015 also offers all of the same facilities and extends the frequency range to 1 MHz. With the ACP 2015 driving a digital storage oscilloscope, switching losses in power-semiconductor circuits can be examined in detail. Both series have fast response and faithfully reproduce rapid changes in the measured current.

MICRO-flex ACP 2005 probes carry safety approvals to EN61010-2-032 600V CATIV and can be used in hazardous areas; they offer a maximum safe voltage rating of 1000 V, ACrms or DC. They can be powered from two AA alkaline batteries, or an external supply of 3V at 100 mA, and the integrator unit measures 110 x 65 x 23 mm.