傳感器是一種檢測裝置，能感受到被測量的信息，并能將感受到的信息，按一定規律變換成為電信號或其他所需形式的信息輸出，以滿足信息的傳輸、處理、存儲、顯示、記錄和控制等要求。

傳感器包括溫度傳感器：如熱電阻、熱電偶。壓力傳感器。流量傳感器等

變送器是把傳感器的輸出信號轉變為可被控制器識別的信號（或將傳感器輸入的非電量轉換成電信號同時放大以便供遠方測量和控制的信號源）的轉換器。傳感器和變送器一同構成自動控制的監測信號源。不同的物理量需要不同的傳感器和相應的變送器。

變送器的種類很多，用在工控儀表上面的變送器主要有溫度變送器、差壓變送器、壓力變送器、液位變送器、流量變送器、電流變送器、電壓變送器、功率變送器等。

信號隔離器是將輸入的信號，如電流信號、電壓信號、熱電阻信號、熱電偶信號等，變送輸出隔離的線性的電流或電壓信號，并提高輸入、輸出、電源之間的電氣隔離性能。

The difference and connection between sensors, transmitters and signal isolators

Sensor is a kind of detection device, which can sense the measured information and transform the sensed information into electrical signals or other required forms of information output according to certain rules to meet the requirements of information transmission, processing, storage, display, recording and control.

Sensors include temperature sensors such as thermal resistors and thermocouples. Pressure sensor. Flow sensors, etc.

A transmitter is a converter that converts the output signal of a sensor into a signal recognized by the controller (or a signal source that converts the non-electrical input of the sensor into an electrical signal and amplifies it for remote measurement and control). Sensors and transmitters together form an automatic monitoring signal source. Different physical quantities require different sensors and corresponding transmitters.

There are many kinds of transmitters. The main transmitters used in industrial control instruments are temperature transmitter, differential pressure transmitter, pressure transmitter, liquid level transmitter, flow transmitter, current transmitter, voltage transmitter, power transmitter and so on.

Signal isolator is to transmit the input signal, such as current signal, voltage signal, thermal resistance signal, thermocouple signal, etc., to output the isolated linear current or voltage signal, and improve the electrical isolation performance between input, output and power supply.