Accurate current measurement transducer for test and measurement applications

LEM provides record levels of accuracy performance in current sensing with the launch of its IN 200 current measurement transducer.

Claimed to be the most accurate sensor of its kind on the market, it is perfect for employment in demanding applications such as high-precision test and measurement equipment employed to analyse the efficiency of inverters fitted to HEVs and EVs. The device can deliver significant performance improvements – specifically in terms of linearity, offset and noise immunity – over conventional fluxgate transducers through its usage of a new kind of digital technology.

Unparalleled levels of accuracy are fulfilled in linearity and electrical offset. While the device's datasheet quotes 0.6ppm and maximum 10ppm, respectively, in-house tests have demonstrated that the sensor can accomplish linearity below 0.5ppm and offset of +/-5ppm. This compares with competitors' transducers providing +/-20-25ppm.

The device completes the company's IN family of High Precision sensors, covering a current range from 100A to 2000A. It is effectively three products able to match nominal currents of 100A, 200A and 400A.

The single most noteworthy factor that sets the device apart from the competition is the company's switch from reliance on analogue circuitry to digital integration technology.

"The trend is very clear," says Horst Bezold, founder of Signaltec. "The increasing electrification of transport is putting huge pressures on test benches for inverters in the automotive sector and has generated a boom in demand for T&M equipment. LEM has come up with a market-leading solution that will help to ease these pressures. By eliminating traditional reliance on analogue technology, we have made it possible to reach levels of accuracy that nobody in the market has ever been able to reach. This is great news for the T&M sector."

The device provides users many other benefits, including significant noise reduction and exceptional immunity to external fields. The device's digital technology provides immunity to temperature effects, interference and supply voltage variation. At the same time, the top-quality metallic housing improves EMC immunity, lowers temperature drift and allows high-precision operation over an extended temperature range (-40C to +85C). Other features include extensive frequency bandwidth – DC to 1.1 MHz (-3dB) – compact design with a 28mm aperture for cables and busbars, and a status signal to indicate transducer state.