What isTemperature Sensor
A temperature sensor is a device, typically, a thermocouple or resistance temperature detector, that provides temperature measurement in a readable form through an electrical signal. A thermometer is the most basic form of a temperature meter that is used to measure the degree of hotness and coolness. A temperature sensor is a device that is designed to measure the degree of hotness or coolness in an object. The working of a temperature meter depends upon the voltage across the diode. The temperature change is directly proportional to the diode’s resistance. The cooler the temperature, the lesser will be the resistance, and vice-versa.
Advantages of Temperature Sensor
Temperature sensors are low-cost, precise, and extremely reliable in repeated experiments.
They are desirable for both embedded and surface mount applications.
They have a faster response time because of the lower thermal mass.
The vibrating wire type is normally full-interchangeable. It means that one indicator can be used for all sensors. It also has a particular technology for verifying long-term stability, simple and fast output.
They generally have an IP-68 rate by their weather-proof body.
They have some indicators that are suitable for direct temperature presentation. So, they can be used for remote detecting and data logging.
Their temperature probes have precise linearity and low hysteresis.
Finally, it should be said that temperature sensors are completely airtight. They are fully sealed by electron beam welding with a pure vacuum inside them.
Why Choose Us
Our Factory
Xian Baochen Information Technology Co., Ltd. is located in high-tech Zone, Xi 'an, Shaanxi Province, China, is a focus on sensors, transmitters, inverters, power semiconductor devices and supporting instruments R & D, manufacturing, sales and service enterprises.
Wide Range of Applications
Through the EU CE, RoHs testing, products are widely used in petrochemical, water conservancy and hydrology, machinery and equipment, automobile manufacturing, industrial process control, weighing measurement, people's livelihood applications and other fields.
Strict Quality Control System
Able to efficiently produce large quantities of products, advanced production processes and stable supply chains, the implementation of strict quality control system. Constantly introduce new technologies and new materials to improve product performance and production efficiency.
Our Service
Able to quickly respond to customer needs, to provide personalized customization, timely delivery, professional technical support and perfect after-sales service.
Temperature Range: Determine the temperature range over which you need to measure. Some sensors are suitable for a wide range, while others are more limited.
Accuracy: Consider the level of accuracy required for your application. Some sensors, like RTDs, provide high accuracy, while others, like thermocouples, offer a broader range but with slightly lower accuracy.
Response Time: Different sensors have different response times. In applications where quick temperature changes need to be captured, such as in control systems, a fast response time is crucial.
Stability: Some sensors, like RTDs, are known for their stability over time. If long-term accuracy is important for your application, stability becomes a critical factor.
Linearity: Ensure that the sensor provides a linear response within the temperature range of interest. This simplifies the calibration and conversion of electrical signals to temperature readings.
Environmental Conditions: Consider the environmental conditions in which the sensor will be used. Some sensors are more suitable for harsh environments or conditions with electromagnetic interference.
Cost: Different sensors come at different price points. Ensure that the sensor you choose fits within your budget while still meeting your requirements.
Sensor Size and Form Factor: The physical size and form factor of the sensor may be important, especially in applications with limited space.
Calibration and Interfacing: Consider the ease of calibration and the interfacing requirements for the sensor. Some sensors may require specialized interfaces or signal conditioning.
Long-Term Reliability: For applications where reliability over time is essential, choose a sensor with a proven track record of long-term performance.
Industry Standards: Some industries have specific standards or requirements for temperature sensors. Ensure that the sensor you choose complies with these standards if applicable.
Measurement Method: Decide whether you need contact or non-contact temperature measurement. For non-contact measurement, consider infrared sensors or thermocouples, while contact methods include RTDs and thermistors.
Power Consumption: If your application has power constraints, consider the power consumption of the sensor.
Mounting and Installation: Consider the ease of mounting and installing the sensor. Some sensors may require special mounting considerations.
Negative Temperature Coefficient (NTC) thermistor
A thermistor is a thermally sensitive resistor that exhibits a continuous, small, incremental change in resistance correlated to variations in temperature. An NTC thermistor provides higher resistance at low temperatures. As temperature increases, the resistance drops incrementally, according to its R-T table. Small changes reflect accurately due to large changes in resistance per ℃. The output of an NTC thermistor is non-linear due to its exponential nature; however, it can be linearized based on its application. The effective operating range is -50 to 250 ℃ for glass encapsulated thermistors or 150℃ for standard thermistors.
Resistance Temperature Detector (RTD)
A resistance temperature detector, or RTD, changes the resistance of the RTD element with temperature. An RTD consists of a film or, for greater accuracy, a wire wrapped around a ceramic or glass core. Platinum makes up the most accurate RTDs while nickel and copper make RTDs that are lower cost; however, nickel and copper are not as stable or repeatable as platinum. Platinum RTDs offer a highly accurate linear output across -200 to 600 ℃ but are much more expensive than copper or nickel.
Thermocouples
A thermocouple consists of two wires of different metals electrically bonded at two points. The varying voltage created between these two dissimilar metals reflects proportional changes in temperature. Thermocouples are nonlinear and require a conversion with a table when used for temperature control and compensation, typically accomplished using a lookup table. Accuracy is low, from 0.5 ℃ to 5 ℃ but thermocouples operate across the widest temperature range, from -200 ℃ to 1750 ℃.
Semiconductor-based temperature sensors
A semiconductor-based temperature sensor is usually incorporated into integrated circuits (ICs). These sensors utilize two identical diodes with temperature-sensitive voltage vs current characteristics that are used to monitor changes in temperature. They offer a linear response but have the lowest accuracy of the basic sensor types. These temperature sensors also have the slowest responsiveness across the narrowest temperature range (-70 ℃ to 150 ℃).
What Is the Difference Between a Temperature Transmitter and a Temperature Sensor
Temperature sensors use an electrical signal to measure temperature. Solids, liquids, and gases may all be measured with temperature sensors. In a nutshell, although they come in various shapes and sizes, they only monitor the temperature change like a room thermostat.
Temperature sensors can detect whether or not a temperature change has happened, but they do not convey a signal regarding the change. That’s when the temperature transmitter comes into the picture.
The temperature transmitter attached to the sensor — sends out a signal when the temperature changes. This allows a technician to inspect the equipment. The temperature transmitter often sends a signal to a system or a monitor that has to read the temperature. That way, if the machine's temperature is off, it can be examined and fixed before it causes difficulties.
Temperature sensors measure temperature readings through electrical signals. They contain two metals that produce a voltage or resistance when the temperature changes.
The sensors play a vital role in maintaining specific temperatures in a variety of industries, including medical applications, HVAC systems, and the appliances in our homes. Temperature sensors are critical to the accuracy and temperature control of such industries.
Temperature sensors work by measuring the voltage across the diode terminals. As the voltage rises, so does the temperature, and then a voltage drop occurs between the transistor terminals and the emitter (in the diode).
There are different types of sensors, which are classified according to their connections. Temperature sensors fall into two main categories, depending on the type of application used or the industry you work in.
Contact temperature sensors measure the hot or cold level of an object or substance by direct contact. They are commonly used to detect various temperatures in different solids, liquids or gases.
These thermometers never come into direct contact with an object or substance, and therefore, they are widely used in hazardous environments such as the power plant industry. They measure the heat or coldness of something through the radiation emitted by the heat source.
What Applications Use Temperature Sensors
Medical Applications
Temperature sensors are used for quick and accurate measurements of patient temperatures. They are also used in MRI imaging machines and portable ultrasound scanners.
Electrical Appliances In Our Homes
Temperature sensors are used in many electrical appliances that you probably didn’t know about. They are found in refrigerators to keep food and drinks cold, in ovens for cooking food to specific heats, and in air conditioners/wall heaters. They are also found in battery chargers to prevent under charging and overcharging electrical appliances.
Oil Mining
Temperature sensors are fundamental for safe and effective practices in the oil mining industry. Oil drills are equipped with inbuilt temperature sensors that notify workers when they need to stop drilling.
Vehicles
Temperature sensors are found in radiators inside different vehicles. These warn you if the temperature of the engine becomes too hot, which prevents the engine from exceeding its temperature limit. They are also used in climate control settings, allowing you to cool or warm the inside of the vehicle.
HVAC Systems
HVAC systems require temperature sensors to provide optimal temperatures for a particular room or building. They are also useful for detecting leaks, such as air conditioning units.
Renewable Energy
Renewable energy sources require an effective production of energy to function; therefore, they depend on temperature sensors to regulate and measure temperature. Temperature sensors are required for wind turbines, biomass combustion applications, solar heating pumps, and geothermal monitoring.
Chemical Industries
Chemical industries use high-quality and effective temperature sensors to measure extremely high temperatures in chemical reactions.
Integrated Circuits
Integrated circuits are found in desktop computers, laptops, mobile phones, and other electronic devices we use daily. They are dependent on integrated silicon temperature sensors to avoid overheating.
Errors caused by improper installation
For example, the installation position and insertion depth of the thermocouple cannot reflect the real temperature of the furnace. In other words, the thermocouple should not be installed too close to the door and heating, and the insertion depth should be at least 8 to 10 times the diameter of the protection tube.
Thermal resistance error
When the temperature is high, if there is a layer of coal ash on the protective tube and dust is attached to it, the thermal resistance will increase and hinder the conduction of heat. At this time, the temperature indication value is lower than the true value of the measured temperature. Therefore, the outside of the thermocouple protection tube should be kept clean to reduce errors.
Errors caused by poor insulation
If the thermocouple is insulated, too much dirt or salt slag on the protection tube and the wire drawing board will lead to poor insulation between the thermocouple and the furnace wall, which is more serious at high temperature, which will not only cause the loss of thermoelectric potential but also introduce interference. The error caused by this can sometimes reach 100℃.
Errors introduced by thermal inertia
This effect is especially pronounced when making fast measurements because the thermal inertia of the thermocouple causes the meter's indicated value to lag behind the change in the temperature being measured. Therefore, a thermocouple with a thinner thermal electrode and a smaller diameter of the protection tube should be used as much as possible. When the temperature measurement environment permits, the protective tube can even be removed. Due to the measurement lag, the amplitude of the temperature fluctuation detected by the thermocouple is smaller than that of the furnace temperature fluctuation. The larger the measurement lag, the smaller the amplitude of the thermocouple fluctuations and the larger the difference from the actual furnace temperature.
Precautions for the use of Temperature Sensor
Temperature Sensors are generally designed for different purposes. If they are to be used for purposes other than those specified, they need to be selected according to the environmental conditions of use. When designing the device, it is generally necessary to conduct a Temperature Sensor placement evaluation test first to confirm Use after no abnormalities.
Do not use the Temperature Sensor under too high power, because self-heating can easily cause the resistance value to drop, which may cause the temperature detection accuracy to decrease, which will very easily lead to the malfunction of the device, so you need to refer to it when using it. Heat dissipation factor, pay attention to the external power and voltage of the Temperature Sensor.
Do not use it outside the operating temperature range, and do not apply sudden temperature changes that exceed the upper and lower limits of the operating temperature range. When using the Temperature Sensor alone as the main control element of the device, in order to prevent accidents, be sure to take comprehensive safety measures such as installing a safety circuit and using a Temperature Sensor with equivalent functions.
When using in a noisy environment, please take measures to install a protective circuit and shield the Temperature Sensor (including wires). Do not apply excessive vibration, shock and pressure. Also, do not excessively stretch or bend the wire. Do not apply excessive voltage between the insulating part and the electrode. Otherwise, poor insulation may occur.
Structure of the Temperature Sensor
Sensor unit
This part is what determines the accuracy of the entire device. It is placed inside the protective case after it has been connected to the connector. This is where the transformation of temperature into an electrical signal takes place.
Connecting conductors
The sensor can be connected by 2, 3 or 4 conductors. The material of the conductor is selected based on the conditions of use of the gauge, which ensures durability and accuracy during signal transmission.
Ceramic insulating material
Plays the role of insulation, prevents short circuits and ensures insulation between wires connected to the protective housing. Ceramic insulating material ensures the safety and stability of the device.
Filler
The filler is usually fine alumina powder, which is dried and vibrated to fill any gaps in the sensor. This substance helps protect the sensor from vibration and mechanical effects.
Protective cover
Responsible for protecting the sensor unit and connecting wires inside. It is made from sturdy materials, suitable for use conditions and sensor size. In some cases, the protective cover may be covered with additional layers for added protection.
Connector
Usually made of an insulating material such as ceramic, containing circuit boards, allowing a resistive connection. When necessary, converters with current strengths from 4 to 20mA can be installed instead of terminal panels, making signal transmission more flexible and efficient.
FAQ
As one of the leading temperature sensor manufacturers and suppliers in China, we warmly welcome you to wholesale cheap temperature sensor in stock here from our factory. All customized products are with high quality and competitive price.
ultrasonic level gauge, sic device, ultrasonic flowmeter