Current sensor, LEM current sensors are top-of-the-line affordable equipment that have a long list of features. Some of these critical features include: Precise Measurement: The current sensors can measure electrical amperage with precision as well as accuracy in the order of mill amperes easily. Low Thermal Drift: All the current sensors feature a low thermal drift that allows the sensor to be used for a prolonged period without any deviation in the accuracy of readings due to heat.