Sensor is a general term for a device or apparatus can be measured by the provisions and converted into usable output signal in accordance with certain rules, usually contains sensitive components and conversion elements. When the sensor output signals to a predetermined standard, it is called the transmitter. The concept of the transmitter is instrument that transmit non-standard electrical signal to an electrical signal of a standard. and the sensor is a device transmit physical signals into electrical signals.
The sensor and transmitter is a kind of thermal instrumentation.sensor is to convert Non-electric physical quantities such as temperature, pressure, level, material, and other characteristics of a gas into electrical signals or physical quantities such as pressure, level, etc. directly to the transmitter. The transmitter is the sensor to the weak signal amplification in order to transfer or launch control elements. Or transmit the non-power sensor inputs into electrical signals at the same time in order to enlarge the distance for measurement and control of the signal source. May also be required for the digital analog converting. The sensor and transmitter together constitute the automatically controlled monitoring source.