High-accuracy current transducers

Paul Boughton

LEM extends its range of high-accuracy current transducers with the new series of IT xx5 transducers for non-intrusive and isolated nominal measurements of DC, AC and pulsed currents from 60 A to 600 A. The range includes four new models: IT 65-S, IT 205-S, IT 405-S and IT 605-S.

These new models offer an extended operating temperature range of -40 to +85°C, compared to the +10 to +50°C temperature range of previous IT models, allowing their use in a wider range of applications, including high precision power supplies, medical equipment, calibration units, precision and high stability inverters, power analysers and metering.

These new models provide the high performance of fluxgate technology based transducers across the extended temperature range, delivering extremely high accuracy with linearity over temperature range better than 12 ppm, and a low offset over temperature range between  36 to 400ppm (according to the model). The fast response time to di/dt step changes is less than 0.5µs, due to a precise and consistent winding process.

IT xx5 series has been designed to operate from a bipolar ±5V DC power supply

The IT xx5 series has been designed to operate from a bipolar ±5V DC power supply and will accommodate round primary conductors of 26 and 30mm diameter, depending upon the model used. In addition to their normal current output, the transducers offer an additional output indicating the transducer state (low or high output levels) and an external LED showing normal operation.

The new IT xx5 range is also fully compatible with the previous LEM IT range, fitting the same footprint. These transducers can be easily retrofitted into old installations while maintaining the various compact sizes for each current range and a variety of panel mounting topologies (flat or vertical), without compromising the high insulation level provided between the primary and measurement circuits.