What is a KTY temperature sensor and how does it work?

Pressure sensor is a common sensor in industrial practice, and has a wide range of applications in various industrial automation environments, such as water conservancy and hydropower, railway transportation, aerospace and other fields. Pressure sensors are used in different locations and have different performance metrics. Therefore, when selecting a pressure sensor, it is necessary to understand the performance indicators and application scope of the sensor.

Below, I will introduce to you the performance index parameters of the pressure sensor. Rated pressure range The rated pressure range is the pressure range that meets the specified values of the standard. That is, between high and low temperatures, the sensor outputs a pressure range that conforms to the specified operating characteristics.

In practice, the pressure measured by the sensor is within this range. Maximum Pressure Range The maximum pressure range is the maximum pressure that the sensor can withstand for a long time.

The structure of the KTY84 temperature sensor chip is based on the principle of diffusion resistance, and the main component is silicon. The temperature range of the KTY84 series is -40 300 and can be used for temperature measurement in exhaust and heating systems.

Temperature sensor working principle: The metal expansion principle designs the sensor metal after the ambient temperature changes, so the sensor can signal this reaction in different ways.

A temperature sensor is a sensor that senses the temperature and converts it into a usable output signal. Temperature sensors are the heart of temperature measuring instruments and come in a wide variety of varieties. According to the measurement method, it can be divided into two categories: contact and non-contact, and according to the characteristics of sensor materials and electronic components, it can be divided into two categories: thermal resistance and thermocouple.

Resistance sensing: With the change of temperature, the resistance value of the metal also changes, for different metals, the resistance value changes differently for each degree of temperature change, and the resistance value can be directly used as an output signal.

1. Positive temperature coefficient:

An increase in temperature = an increase in resistance.

Lower temperature = less resistance.

2. Negative temperature coefficient:

Increased temperature = decreased resistance.

Decrease in temperature = increase in resistance.

In addition to thermocouples using the Seebeck effect, metal and oxygen semiconductors such as PT and W, non-oxide semiconductors, and organic semiconductors are commonly used as temperature sensors for temperature measurement. In addition, there are sensors that detect changes in the resonance frequency by using the change of current-voltage characteristics at the PN junction with temperature, sensors that use the change in magnetic properties and dielectric constant near the Curie temperature, and sensors that use the change in dielectric constant and piezoelectric constant to detect the temperature of the change in resonance frequency. The most common application example is the temperature control of air conditioners.

The temperature sensor senses the change of temperature, so that the resistance value of the sensitive components (such as thermistors, thermocouples, etc.) changes, so that the output voltage changes in the circuit.

1. The working principle of thermocouple sensors.

When there are two different conductors and semiconductors A and B form a circuit, and their two ends are connected to each other, as long as the temperature at the two nodes is different, the temperature at one end is t, which is called the working end or hot end, and the temperature at the other end is to, which is called the free end or cold end, then there is a current generated in the loop, that is, the electromotive force present in the loop is called thermal electromotive force. This phenomenon of electromotive force due to different temperatures is known as the Seebeck effect. There are two effects associated with Seebeck:

First, when an electric current flows through the junction of two different conductors, heat is absorbed or released (depending on the direction of the current), which is called the Peltier effect. Second, when an electric current flows through a conductor with a temperature gradient, the conductor absorbs or emits heat (depending on the direction of the current relative to the temperature gradient), which is called the Thomson effect. The combination of two different conductors or semiconductors is called a thermocouple.

2. The working principle of the resistance sensor.

The resistance value of the conductor changes with the change of temperature, and the temperature of the measured object is calculated by measuring its resistance value, and the sensor composed of this principle is the resistance temperature sensor, which is mainly used for temperature measurement in the temperature range of -200-500. Pure metal is the main manufacturing material of RTD, and the material of RTD should have the following properties:

1) The temperature coefficient of resistance should be large and stable, and there should be a good linear relationship between the resistance value and temperature.

2) High resistivity, small heat capacity and fast reaction speed.

3) The reproducibility and manufacturability of the material are good, and the first is low.

4) The chemical and physical properties are stable within the temperature measurement range.

At present, platinum and copper, which are the most widely used in industry, have been made into standard temperature measurement thermal resistances.

Most of the temperature sensors are resistive sensors, that is, they themselves are a resistor, with the change of temperature, its resistance value also changes accordingly, the resistance value of the ideal temperature sensor changes in a linear relationship with the temperature change, but in fact it does not exist, the general performance is that there is a good linear performance in a certain temperature range. Therefore, when choosing a temperature sensor, it is necessary to understand the operating temperature range of the specific model original.

Good luck.