Sensor is able to provide a certain accurate signal value of device stability. Transformer can meet the sensor using conditions. National standard GB7665-1987 under the sensor is defined as: "can feel the provisions is measured and converted into usable signal device according to certain rules or device, usually by sensitive components and conversion components". Sensor is a kind of testing device, can feel the measured information, and can detect feel the information, will change according to certain rule become electrical signal output, or other form of information needed to satisfy the information transmission, processing, storage, quality, record and control requirements. It is the main link to realize automatic detection and automatic control. This definition, a specific transformer can be within the scope of the sensor.

See the most typical significance and application of hall voltage and current sensors are widely by using the principle of hall effect (coil) of voltage, current, power, frequency, today, impedance and wave electric parameter measurement. As electricity isolation sensor transmitter, can to the scene of the large current, high voltage, power, frequency, phase Angle, power and other electrical pompano isolation measurement and transformation, can also be for a variety of weak signal (such as special bridge road signals) in isolation amplifier and transformation, to regulate, transformed to conform to the international general standard of voltage, current, frequency, analog signals into digital quantity, such as switch status signal output, etc. These can output signal and the traditional pointer instrument, also can with modern digital control instruments, all kinds of A/D converter and directly connected to the computer system, which can form A high reliability industrial test (monitoring) or control system. As small power isolation sensor in the application, the user does not need to do secondary development work, to the voltage or current signal can be directly connected to the product (through the terminal, pin input or wear a few input), get together the output signal. Therefore, electricity isolation sensors as a signal conditioning, isolation and transform function module. Is a relatively ideal industrial control and data acquisition system of the send products.

With the continuous development of science and technology, industrial control or test (monitoring) system is becoming more and more high to the requirement of electric quantity isolation sensor, especially in terms of stability, precision and function of product. Digital products whether universals can or features (such as nonlinear correction and small signal processing), the analog products are incomparable. Therefore, the digital power isolation sensor - kind of inevitable trend. Will also gradually away from the category of sensor, so the transformer in the direction of the standardization of their development.