The difference between a temperature transmitter and a temperature sensor

Core features

1. Temperature sensor

The core function of temperature sensors (e.g., PT100, PT1000, thermocouples, etc.) is to directly sense temperature changes and convert them into electrical signals (e.g., resistance values, voltages, or currents).

Features: direct contact with the object to be measured or the environment, such as plug-in, patch installation; There are various types of output signals, including resistive signals (e.g., 100Ω for 0°C for PT100), analog voltages, or digital signals.

2. Temperature transmitter

The temperature transmitter is responsible for amplifying, linearizing, and normalizing the original signal output from the sensor, and converting it into an industrial-purpose signal (such as 4-20mA current, 0-10V voltage, or RS485 digital signal).

Features: Built-in signal processing module, providing cold contact compensation, anti-interference filtering and other functions to improve signal stability; It supports adjustable measuring range and can flexibly adapt to the needs of different temperature measurement ranges.

Structure and composition

1. Temperature sensor: It is usually packaged by a single sensitive element (such as platinum resistance, thermocouple), and has a simple and compact structure, which is suitable for direct embedding in equipment or installation in confined spaces.

2. Transmitter output: converted into standard industrial signals (such as 4-20mA, 0-10V), with strong anti-interference ability, suitable for long-distance transmission, and can be directly connected to DCS, SCADA and other systems.

Output signal

1. Sensor output: mostly non-standard signals, such as the resistance change of PT100 and the microvolt voltage of the thermocouple. These signals require additional circuit processing before they can be read by the control system.

2. Transmitter output: converted into standard industrial signals (such as 4-20mA, 0-10V), with strong anti-interference ability, suitable for long-distance transmission, and can be directly connected to DCS, SCADA and other systems.

Selection points

1. Cost consideration: the unit price of the temperature sensor is low, but it needs to be used with a transmitter; Integrated transmitters are more costly, but save time during installation and commissioning.

2. Environmental adaptability: In high-temperature and corrosive environments, it is necessary to choose a sensor or split transmitter with a higher protection level.

Temperature sensors and transmitters have different roles in the temperature measurement chain: the former collects data, the latter optimizes the signal. Understanding the difference between the two can help you choose the best solution based on your actual needs (e.g., accuracy, transmission distance, cost).