LEM claims IN 200 is world’s most accurate current measurement transducer
Record levels of accuracy performance in current sensing are claimed for the IN 200 current measurement transducer. It is says LEM, the most accurate sensor of its kind available and is suitable for use in high precision test and measurement equipment used to analyse the efficiency of inverters fitted to hybrid electric vehicles (HEVs) and electric vehicles (EVs).
According to LEM, the IN 200’s use of digital technology enables it to offer significant performance improvements, particularly in terms of linearity, offset and noise immunity, over traditional fluxgate transducers.
Traditionally, many analogue circuits would be required to cancel out noise and other impacts of having different fluxgate coils but LEM has reduced the number of analogue circuits within the transducer through digital integration, transforming the signal. By operating in the digital domain, the sensor offers a wider range of capabilities, including ripple compensation, detecting second harmonics and voltage regulator excitation.
“Unparalleled levels of accuracy” are achieved in linearity and electrical offset, continued LEM. The IN 200’s data sheet quotes 0.6 parts per million (ppm) and maximum 10ppm respectively, although in-house tests have shown that the sensor can achieve linearity below 0.5ppm and offset of +/-5ppm. Competitors’ transducers offer +/-20-25ppm, reported the company.
The IN 200 can be fitted to automotive test benches for manufacturers to improve the testing efficiency of inverters and validate their performance levels. Inverters will reduce power losses allowing designers to have the potential to tackle the issue of “range anxiety” in EVs.
The IN 200 joins existing members of LEM’s IN family of high precision sensors which now cover 100A to 2000A. The IN 200 is capable of matching nominal currents of 100A, 200A and 400A.
Other benefits claimed for the IN 200 include it performance in noise reduction and immunity to external fields. The device’s digital technology ensures immunity to temperature effects, interference and supply voltage variation, said LEM. The metallic housing, rather than a plastic casing, improves EMC immunity, reduces temperature drift and enables high-precision operation over an extended temperature range of -40 to +85 degrees C.
Other features of the IN 200 include a broad frequency bandwidth of DC to 1.1MHz (-3dB) and a compact design with a 28mm aperture for cables and busbars. It also has a status signal to indicate the transducer state.
