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IntroductionIn the modern landscape of technology, precise and reliable measurement is not just an advantage—it's a necessity. Pressure transducers, or pressure sensors, lie at the heart of countless applications, from automotive systems to industrial automation, and even consumer electronics. They quietly and efficiently convert physical pressure into readable signals, acting as the bridge between mechanical force and digital data. If you're curious about how these essential components function or which type best suits your project, you're in the right place. In this comprehensive guide, we'll delve into what pressure transducers are, the different types available, and how to select and utilize them effectively. This article will also provide insights into practical considerations, key specifications, and how they apply across industries. What Exactly is a Pressure Transducer?A pressure transducer is a device that translates pressure into an electrical signal. This function allows real-time monitoring and adjustment in systems where precise pressure levels are crucial. Pressure transducers are often paired with instruments that interpret the output, providing data for everything from routine monitoring to critical safety alerts. How They WorkThe typical pressure transducer contains a sensing element—often a diaphragm or membrane—that deforms under applied pressure. This mechanical deformation changes an electrical property (such as resistance or capacitance) that is then converted into a standardized electrical output. This signal is either analog or digital, depending on the specific transducer, making it easy for connected systems to interpret and act on the data. The Different Types of Pressure TransducersSelecting the right type of pressure transducer begins with understanding the options available. Here's a breakdown of the most common types, each suited to different scenarios and requirements. Strain Gauge Pressure TransducersThese transducers rely on a strain gauge bonded to a flexible membrane. As pressure deforms the membrane, the strain gauge stretches, causing a change in resistance. They are robust, with a straightforward design that makes them popular for industrial and heavy-duty applications. Capacitive Pressure TransducersUtilizing a capacitor formed between a diaphragm and a fixed plate, capacitive transducers are especially sensitive and ideal for low-pressure applications. Their precision makes them well-suited for environments requiring subtle pressure changes, such as in medical devices or scientific instruments. Piezoelectric Pressure TransducersPiezoelectric transducers use crystals that generate a small electric charge when stressed. This type is excellent for dynamic pressure measurements, making it a favorite for high-speed applications like monitoring combustion in engines. Optical Pressure TransducersIn optical transducers, light reflects off a diaphragm within the sensor, and pressure changes are detected through shifts in light patterns. These are non-conductive and highly accurate, ideal for applications in harsh or high-temperature environments where electrical interference is a concern. Each type of transducer has its strengths and limitations, so understanding the specific needs of your application is key to choosing the right one. Key Specifications of Pressure TransducersFor a pressure transducer to perform as intended, its specifications must align closely with your project's demands. Below are some of the most important specs to keep in mind: Pressure RangeDefines the minimum and maximum pressures that the transducer can accurately measure. Selecting a sensor that can handle the expected pressure range, with some margin for unexpected spikes, ensures reliable operation. AccuracyA critical specification, accuracy refers to how close the sensor's output is to the true pressure value. Industrial applications often require higher accuracy than consumer-grade applications. Response TimeMeasures how quickly the transducer responds to changes in pressure. Applications with rapid fluctuations, such as automotive or aerospace, need transducers with low response times to ensure accurate real-time measurements. Temperature SensitivitySince temperature fluctuations can affect accuracy, choosing a pressure transducer with a minimal temperature coefficient is essential, especially in environments where temperatures vary widely. Output TypeAnalog transducers generate a continuous signal that corresponds to the pressure level, while digital transducers output discrete values. Analog is often simpler to process, while digital can be advantageous for applications requiring noise immunity or interfacing with digital systems. By evaluating these specifications, you can better match a transducer to the unique needs of your system, avoiding performance issues and enhancing reliability. Real-World Applications of Pressure TransducersPressure transducers find applications in virtually every industry. Here's a look at some of the more prevalent and interesting use cases: Automotive IndustryIn cars, pressure transducers monitor tire pressure, engine oil pressure, and exhaust gas recirculation. These sensors enhance vehicle safety and optimize performance by adjusting systems based on real-time data. Medical DevicesPressure transducers are vital in equipment like ventilators, infusion pumps, and blood pressure monitors. These sensors help maintain precise control over pressure levels, which is crucial for patient safety. Industrial AutomationIn automated manufacturing, pressure sensors monitor pneumatic and hydraulic systems to ensure processes operate within safe pressure ranges. They also play a key role in leak detection and process control systems. Aerospace and DefensePressure transducers in aerospace applications monitor cabin air pressure, fuel systems, and hydraulic systems to ensure safety and optimal performance under extreme conditions. Consumer ElectronicsEven your smartphone may contain a pressure sensor to estimate altitude, improve GPS accuracy, and measure atmospheric pressure for weather-related applications. The versatility of pressure transducers is a testament to their reliability and adaptability in meeting diverse industry requirements. Selecting the Right Pressure Transducer for Your ApplicationChoosing the best pressure transducer involves more than just looking at specifications—it requires a comprehensive assessment of the environment, application needs, and expected performance. Environmental FactorsConsider the conditions the transducer will be exposed to. Will it face high temperatures, dust, moisture, or corrosive substances? For instance, if a sensor will be used in a chemical processing plant, selecting a model with a corrosion-resistant housing is crucial. Required Sensitivity and PrecisionIf the application involves low-pressure measurements or requires high accuracy (such as in laboratory settings), capacitive or optical transducers might be preferable due to their sensitivity and precision. Cost vs. PerformanceStriking a balance between cost and performance can be challenging. While industrial-grade sensors offer excellent durability and precision, they may be unnecessary for consumer-grade applications, where affordability and moderate accuracy suffice. Integration NeedsDepending on the larger system, you may need a transducer that offers specific electrical interfaces, such as analog output, 4-20 mA current loops, or digital communication protocols like I2C or SPI. Ensuring compatibility reduces integration complexity and cost. Technical Insights into Pressure Transducer Theory and DesignFor those interested in the technical underpinnings, let's dive into some core theory and design principles. Strain Gauge BasicsIn strain gauge pressure transducers, a thin metallic gauge is bonded to a flexible diaphragm. The resistance of the gauge changes as pressure deforms the diaphragm, and this resistance shift is converted into an electrical output. Capacitive DesignCapacitive pressure transducers use a pair of metal plates (one movable) to form a capacitor. Changes in pressure alter the spacing between the plates, which, in turn, changes the capacitance. This change is interpreted as a pressure measurement. Piezoelectric PhenomenonIn piezoelectric transducers, pressure deforms a crystal, generating a small voltage proportional to the force. This unique characteristic allows them to measure rapidly changing pressures and is particularly useful in dynamic environments. These principles form the basis of transducer design and offer a deeper understanding of how these devices operate in real-world applications. Practical Tips for Using and Maintaining Pressure TransducersTo get the most out of your pressure transducers, consider these practical tips: Regular CalibrationOver time, transducers may drift from their original calibration due to environmental factors or wear. Periodic calibration ensures ongoing accuracy and reliable measurements. Protection from Extreme ConditionsEven ruggedized sensors can be susceptible to harsh conditions. Protect transducers from extreme temperatures, dust, moisture, or physical impacts to extend their lifespan and prevent damage. Proper MountingMisalignment or improper mounting can introduce errors in measurement. Carefully follow mounting guidelines to ensure accuracy, especially in dynamic or high-vibration environments. Monitor for Signal DriftIn critical applications, any deviation in the sensor's output can indicate a problem. Regularly check readings for signs of drift, and address any issues immediately to maintain reliability. ConclusionPressure transducers are indispensable tools in the measurement and control landscape. Understanding their types, specifications, and practical considerations can make all the difference in ensuring your systems operate safely and efficiently. From automotive and aerospace to consumer electronics, these sensors enable the accurate measurement and monitoring necessary for reliable performance. By selecting the right type of pressure transducer, considering key environmental and integration factors, and adhering to maintenance best practices, you can harness their full potential in your projects.

Introduction Linear Displacement Sensor, also called Linear Transducer or Linear Potentiometer Sensor, is a device used to monitor and measure linear position, which convert mechanical physical quantities into electrical signals. Linear potentiometer is a type of variable resistance sensor, designed to measure the displacement of a slider or wiper in a linear direction. Also known as a slider or pot, linear potentiometers produce a changing rate of resistance, dependent on the position of a slider or wiper. LVIT Linear Position Sensor Technology Catalog Introduction Ⅰ Linear Displacement Sensor Working Principle Ⅱ Linear Potentiometer Sensor Design Parameters Ⅲ Linear Transducer Applications Ⅳ Linear Displacement Sensor Types Recommendation Ⅴ Linear Potentiometer Sensor Installation Ⅵ Linear Transducer Operating Requirements Ⅶ Linear Displacement Sensor Use Matters Ⅷ FAQ Ⅰ Linear Displacement Sensor Working Principle The function of the linear displacement sensor is to convert the linear mechanical displacement into an electrical signal. In order to achieve this effect, the sensor slide rail is connected to a steady-state DC voltage, allowing a small current of microamperes to flow, and the voltage between the slide and the starting end is proportional to the length of the slide. Using the sensor as a voltage divider can minimize the requirements for the accuracy of the total resistance of the sliding rail, because the resistance change caused by the temperature change will not affect the measurement result. The linear displacement sensor is actually a sliding rheostat. Using the sensor as a voltage divider can minimize the requirements for the accuracy of the total resistance of the sliding rail, because the resistance change caused by the temperature change will not affect the measurement result. Figure 1. KTC 300mm Linear Displacement Sensor Ⅱ Linear Potentiometer Sensor Design Parameters For the general linear displacement sensor:Wear resistance life: >100X106 timesLinear accuracy error: <0.05%Repeatability error: <0.005mmMaximum moving speed: 10m/sImpact factor: IEC 68-2-29:1968 50gVibration factor: IEC 68-2-6:1982 20gMaximum allowable voltage: DC60V/5KΩ～20KΩ; DC36V/2KΩ～4KΩ; DC24V/1KΩTemperature drift coefficient: <1.5ppm/℃ Figure 2. KTR-75mm Linear Displacement Transducer Ⅲ Linear Transducer Applications 1) KTC, KTM, LS tie rod structure is a general structure, with optional pull ball universal head or universal head, can reduce the adverse effects caused by the installation of non-neutral. They are suitable for injection molding machines, textile machinery, woodworking machinery, etc.2) KPC and KPM fixed belts at both ends are hinged and sporty, suitable for swinging, and in measurement systems where the sensor body cannot be fixed, and the sensor will move with the measurement movement.3) KTF and KFM slider types are suitable for the application of the smallest installation length size. With the extension arm, it can eliminate the adverse effects of installation misalignment.4) KTR type is a miniature self-recovery rod structure, no need to tow and install.5) KPF type can also detect the internal displacement of the cavity. Figure 3. KPM Linear Displacement Sensor Ⅳ Linear Displacement Sensor Types Recommendation 🔺Tie Rod TypeUniversal drawbar conductive plastic film series, effective stroke 75mm ~ 1250mm, 4mm buffer stroke at both ends, precision 0.05%~ 0.04%FS. The surface of the shell is anodized, anti-corrosion.Built-in conductive plastic measuring unit, no temperature drift, long life, and automatic electrical grounding function. The sealing grade is IP67, DIN430650 standard plug and socket, which can be applied to most general occasions.The tie rod ball joint has 0.5mm automatic centering function, and the allowable extreme movement speed is 10m/s.🔺Sliding TypeGeneral-purpose slider conductive plastic film series, effective stroke 75mm～3000mm, 4mm buffer stroke at both ends, precision 0.05%～0.02%FS. The surface of the shell is anodized, anti-corrosion.Built-in conductive plastic measuring unit, no temperature drift, long life, and automatic electrical grounding function. The sealing level is IP54 (IP57 when installed downwards), DIN430650 standard plug and socket, which can be used in most general occasions, especially the length direction is limited, the alignment is difficult.The tie rod with the ball head has 10mm automatic correction function, and the allowable limit motion speed is 10m/s. Figure 4. KPC Linear Displacement Sensor Ⅴ Linear Potentiometer Sensor Installation 1) The installation of the linear displacement sensor should balance two ends. Do not tighten the fixing bracket screws before the limit position is determined. The linear displacement sensor fixing bracket screws can be locked after adjusting the stroke.2) The pull-ball universal head of the tie-rod displacement sensor allows a centering deviation with a radius of 1mm. Of course, the shorter the specification, the smaller the centering deviation is recommended.3) After fixing the linear displacement sensor, when retracting the tie rod, the cylindrical body of the universal ball head should be able to have gaps in the four radial directions. Or adjust the mounting position of the universal head or the mounting bracket position near the extended end.4) If there is a big misalignment when the pull rod is pulled out, adjust the mounting bracket near the end of the plug. This can be used as an auxiliary review method.5) The mounting rod of the pull ball universal head and the pull rod are allowed to tilt at an angle of 12°. However, if the centering deviation and tilt deviation are both large during installation, the stability and service life of the electronic ruler will be affected. So further adjustment is required.6) The slider electronic ruler can reduce the workload of adjusting the neutrality, but the auxiliary extension rod cannot be cancelled. Because the stability and service life due to the poor neutralization will occur, and even damage the sensor.7) After all adjustments are made, tighten the mounting screws to make the grounding resistance less than 1. Measure the resistance between the cover screw of the potentiometer sensor and the mounting bracket with a multimeter in the 200 block.8) When using a four-wire system or wiring with a shielded wire, the grounding end of the linear potentiometer should be connected, and the fourth end or shielding wire should be grounded at the end of the electric control box correctly. Figure 5. KTM Linear Displacement Sensor Ⅵ Linear Transducer Operating Requirements 🔺The supply voltage should be stable.Industrial power supply requires ±0.1% stability. For example, the reference voltage is 10V, and the fluctuation of ±0.01V is allowed under the fluctuating voltage. Otherwise, it will cause the displayed trap to fluctuate. 🔺Prevent electrostatic interference.Electrostatic interference and FM interference can easily make the digital display of the linear displacement sensor jump. Separate the strong current line of the equipment from the signal line of sensor in a wire duct. The potentiometer should use a grounding support, and its shell (the resistance between the end cover screw and the support should be less than 1Ω) must be well grounded. The signal line should be shielded and well grounded where at one end of the electrical box.In the case of electrostatic interference, the voltage measurement of the general multimeter is normal, but it shows the digital beating, even the phenomenon is the same when the high-frequency device is interfered. To verify whether it is electrostatic interference, use a power cord to short-circuit the cover screw of the sensor with a certain point of metal on the machine. However, it is difficult to eliminate high-frequency interference by the above-mentioned methods, which occurs frequently in robots and inverters. Stopping the robot or the inverter power saver can test it. 🔺WiringLines "1" and "3" are power lines, and "2" is the output line. Once the above line is connected wrongly, there will be large linear errors, resulting in poor control accuracy, and display bounce easily. 🔺The power supply capacity should be sufficient.If the power supply capacity is too small, the following situations are likely to occur: the mold clamping movement will cause the display of the glue injection ruler to jump, or the melt movement will cause the display of the mold clamping potentiometer sensor to fluctuate. Especially when the power supply of solenoid valve drive power supply is combined with the sensor, the above-mentioned situation is prone to occur. In severe cases, the voltage fluctuation can be measured with the voltage file of a multimeter. If the problem cannot be solved, even if the electrostatic interference and high-frequency interference are eliminated, the neutrality is also bad. At this time, you can check the power supply efficiency. 🔺Installation angleThe angle tolerance is ±12°, and the parallelism tolerance is ±0.5mm. If both are too large, it will cause the display number to jump. In this case, the angle and parallelism must be adjusted. 🔺Prevent short circuit.During the working process of the displacement sensor, the data is regularly displayed at a certain point or no data. In this case, it is necessary to check whether the connection line insulation is damaged and the ground short circuit caused by regular contact with the machine's metal casing. 🔺Avoid aging.For the linear displacement sensor that has been used for a long time, the seal is aging, there may be a lot of impurities, such as oil and water mixture, which affect the contact resistance of the brush, and cause the display number. It can be considered as the early damage of sensor. Figure 6. KTF Linear Displacement Sensor Ⅶ Linear Displacement Sensor Use Matters 1) If the potentiometer sensor has been used for a long time, and the seal has been aging, there are a lot of impurities mixed in, and the water mixture and oil will seriously affect the contact resistance of the brush, which will cause the displayed number to jump continuously. At this time, it can be said that the electronic ruler of the linear displacement sensor has been damaged and needs to be replaced.2) If the capacity of the power supply is small, there will be many situations. Therefore, the power supply should have sufficient capacity. Because insufficient capacity will cause the following situation: The movement of the melt will change the display of the sensor to cause the fluctuations,  resulting in a large error in the measurement result.If the driving power of the solenoid valve and the power supply of the linear displacement sensor are at the same time, the above situation is more likely to occur. In serious cases, the voltage range of the multimeter can even measure the relevant fluctuations of the voltage. If the situation is not caused by high-frequency interference, electrostatic interference, or insufficient neutrality, then it may be caused by the small power supply.3) FM interference and electrostatic interference may cause the digital scale of the linear displacement sensor to jump. The signal line of the sensor and the strong current line of the equipment should be separated from the wire duct. Use the grounding support to have good contact with the ground. The signal wire needs to use a shielded wire, and a section of the electrical box should be grounded to the shielded wire.If there is high-frequency interference, the voltage measurement with a multimeter will usually display abnormally. When there is electrostatic interference, the situation is the same as that of high-frequency interference. To prove whether it is electrostatic interference, you can use a power cord to short-circuit the cover screw of the sensor with some metal on the machine. As long as it is short-circuited, the e-interference will be eliminated immediately. However, if you want to eliminate high-frequency interference, it is difficult to use the above method. Frequency-conversion power savers and robots often have high-frequency interference, so you can try to stop them to verify the interference.4) The power supply voltage must be stable. The industrial voltage needs to meet the stability of ±0.1%. For example, if the reference voltage is 10V, a fluctuation of ±0.01V can be allowed. If it is not, it will cause a display fluctuation. But if the amplitude of the display fluctuation at this time does not exceed the amplitude of the fluctuation voltage, then the potentiometer sensor is normal.5) As for the linear displacement sensor installation, the parallelism can be allowed to have an error of ±0.5mm, and the angle can be allowed to have an error of ±12°. However, if both are too large, then the display number will be bounced. So the parallelism and angle must be adjusted.6) During the connection process, be sure to pay more attention, the wires of the potentiometer sensor cannot be connected wrongly.   Ⅷ FAQ 1. What is a linear displacement sensor?A linear displacement sensor is a device used to monitor and measure linear position. They can also be called Linear Position Sensors or Linear Transducers. They are available in different sizes to measure different stroke lengths.   2. How does a linear displacement sensor work?Linear displacement transducers are linear sensors that work on the magnetostrictive principle, whereby a torsional strain pulse is induced in a specially designed magnetostrictive waveguide by the momentary interaction of two magnetic fields.   3. What is the linear displacement?Therefore; “Linear Displacement” can be defined as the movement of an object in a linear fashion along a single axis in a straight line, for example; from side to side or up and down. ... Linear Displacement is usually measured in millimetres or inches and has a positive and negative direction.   4. What are linear sensor potentiometers?A linear potentiometer is a type of position sensor. They are used to measure displacement along a single axis, either up and down or left and right. Linear potentiometers are often rod actuated and connected to an internal slider or wiper carrier.   5. What is the difference between linear potentiometer and rotary potentiometer?This potentiometer is similar in function to the rotary potentiometer. The only difference between these two, as the name suggests, is the linear motion of the knob, instead of rotary, for adjusting the resistance.   6. How does a potentiometer sensor work?Potentiometers work by varying the position of a sliding contact across a uniform resistance. ... A potentiometer has the two terminals of the input source fixed to the end of the resistor. To adjust the output voltage the sliding contact gets moved along the resistor on the output side.   7. What does a potentiometer sensor measure?A potentiometer sensor measures the distance or displacement of an object in a linear or rotary motion and converts it into an electrical signal.   8. How does a potentiometer measure displacement?To measure the displacement of the body, this body, which is moving, is connected to the sliding element of the potentiometer. As the body moves, the position of the slider located on the potentiometer also changes so the resistance between the fixed point and the slider changes.

IntroductionThe Temperature Sensor, a measuring instrument, uses various physical properties of a substance to convert the thermal quantity into the physical quantity, including expansion, resistance, capacitance, electromotive force, magnetic properties, frequency, optical characteristics and thermal noise. Many materials and components change with temperature, so there are quite a few materials that can be used as temperature sensors. Here are four temperature sensors in detail.Temperature Sensors ExplainedCatalogIntroductionⅠ Temperature Sensor Types Overview1.1 What is Thermocouple?1.2 What is Thermistor Sensor?1.3 What is Resistance Temperature Detector (RTD)?1.4 What is IC Sensor?1.5 Temperature Sensor Cons and ProsⅡ How to Test: Measuring IndexesⅢ FAQⅠ Temperature Sensor Types OverviewThere are many types of temperature sensors, which can be divided into contact type and non-contact type according to the measurement method; thermistor and thermocouple according to the characteristics of sensor materials and electronic components.The contact temperature sensor needs to maintain thermal contact with the measured medium, so that the two can perform sufficient heat exchange to reach the same temperature. This type of sensor mainly includes resistance type, thermocouple, PN junction temperature sensor and so on. The non-contact temperature sensor does not need to be in contact with the measured medium, but achieves the purpose of temperature measurement through the heat radiation or convection of the measured medium.Here is a detailed introduction to the commonly used four: Thermocouples, Thermistors, Resistance Temperature Detector (RTD), IC Sensor.Figure 1. Temp Sensors (Resistance Changes with Temperature)1.1 What is Thermocouple?Thermocouples are the most commonly used temperature sensors in measurement. Its main advantages are wide temperature range and adaptability to various atmospheric environments, and it is strong, low in price, does not require power supply, and is also the cheapest. The thermocouple consists of two different metal wires connected at one end. When one end of the thermocouple is heated, there is an electric potential difference in the thermocouple circuit, and the measured electric potential difference can be used to calculate the temperature.Figure 2. Metal JunctionsThe thermocouple sensor has two contacts. The measurement end (sometimes called the hot end) is where the two metals connect. The reference junction (also called the cold end) is connected to the measurement circuit. When there is a temperature difference between two ends, an mV signal proportional to the temperature difference is generated. The mV value increases with increasing temperature. The relationship between mV and temperature is non-linear.The thermocouple connector can be constructed by connecting the thermal junction to the outer sheath for grounding or ungrounding (insulating from the sheath). A grounded thermocouple responds faster, but the thermocouple will contact the processing voltage. Therefore, it is important to isolate the measurement circuit to prevent the formation of ground loops and to avoid measurement errors.Figure 3. Thermocouple for Temperature MeasurementInside the temperature component, the thermocouple is usually embedded in magnesium oxide (MgO) and a metal sheath, then insert it into the thermowell or protective tube. This helps protect the sensor from environmental pollution. When magnesium oxide is contaminated with water and salt, even thermocouples that are not grounded will eventually be grounded.As above mentioned, the relationship between voltage and temperature is nonlinear, so it is necessary to make a second measurement for the reference temperature (Tref), and use the test equipment software or hardware to process the voltage-temperature conversion inside the instrument to finally obtain the thermocouple temperature (Tx). Thermocouple is the simplest and most versatile temperature sensor, but its sensitivity is relatively low, which is easy to be affected by environmental interference signals, and the temperature drift of the preamplifier. So it is not suitable for measuring small temperature changes, that is, it is not suitable for high-accurate measurement and application.In actual use, the thermocouple measuring circuit can measure any temperature except 0°C. The measuring circuit must measure the temperature of the cold junction and restore the temperature to 0°C. This kind of electrical compensation is called cold junction compensation (or reference junction compensation). Most thermocouple measurement circuits do this.If the application requires a thermocouple instead of a thermistor, a higher-grade thermocouple is better. In addition, their cost difference is small, and high-quality wire can provide higher stability.🔺Table 1: Thermocouple Types and Application RangesThermocouple TypeApplication Range (℃ / ℉)E95-900℃ (200-1650℉)J95-760℃ (200-1400℉)K95-1260℃ (200-2300℉)N95-1260℃ (200-2300℉)R870-1450℃ (1600-2640℉)S980-1450℃ (1800-2640℉)T0-350℃ (32-660℉) 1.2 What is Thermistor Sensor?The main component of the thermistor sensor is the thermistor, which absorbs heat radiation around.Thermistors are made of semiconductor materials, mostly with a negative temperature coefficient, that is, the resistance decreases with increasing temperature. Temperature changes will cause large resistance changes, so it is the most sensitive temperature sensor. However, the linearity of the thermistor is extremely poor and has huge effects with the production process. So the manufacturer cannot give a standardized thermistor curve.The thermistor is very small and responds quickly to temperature changes. But it needs to use a current source, and its small size also makes it extremely sensitive to self-heating errors.Figure 4. Thermistor SensorThe thermistor measures the absolute temperature on the two lines, with better accuracy, but it is more expensive than a thermocouple, and the measurable temperature range is also smaller than that of a thermocouple. A commonly used thermistor has a resistance value of 5kΩ at 25°C, and a temperature change of 1°C causes a resistance change of 200Ω. Note that the lead resistance of 10Ω only causes a negligible error of 0.05°C. It is very suitable for current control applications that require fast and sensitive temperature measurement. Small size is benefit for applications with space requirements, but care must be taken to prevent self-heating errors.Figure 5. Resistance-TemperatureThe thermistor also has its own measurement tips. With small size, it can quickly stabilize, and will not cause thermal load. However, it is not strong enough, and large currents can cause self-heating. Since the thermistor is a resistive device, any current source will cause heat on it due to power. Power is equal to the product of current squared and resistance. Therefore, a small current source must be used. If the thermistor is exposed to high heat, it will cause permanent damage. 1.3 What is Resistance Temperature Detector (RTD)?RTD is a precision temperature sensor, made of high-purity conductive metal (such as platinum, copper or nickel) or alloy. Its resistance increases with increasing temperature and decreases with decreasing temperature, similar to a thermistor. RTD is like a thermoelectric converter, converting temperature changes into voltage changes. By passing a constant temperature current through the temperature sensor, an output voltage that increases linearly with temperature can be obtained. The most suitable metal for RTD is a pure metal that remains stable within a given temperature range. The resistance-temperature change relationship is preferably linear. The larger the temperature coefficient (it is defined as the resistance change caused by unit temperature), the better, and it must be able to resist thermal fatigue and respond sensitively to temperature changes. A typical RTD has a protective sleeve and a probe. The protective sleeve is mainly used to protect the RTD from being damaged by the measured medium, which is usually made of stainless steel, carbon steel, inconel or cast iron, and its use temperature can reach 1100°C.Figure 6. Resistance Temperature Detector (RTD)It is currently the most accurate and stable sensor, and its linearity is better than thermocouples and thermistors. However, RTD is also a temperature sensor with slow response speed and more expensive price. So it is most suitable for applications that have strict requirements on accuracy, but speed and price are not critical. 1.4 What is IC Sensor?IC sensors can work in a temperature range of -55°C to +150°C, and precise one can operate at temperatures up to +200°C. It is commonly used in fitness tracking applications, wearable products, computing systems, data loggers, and automotive applications. The most common integrated IC temperature sensors are analog output devices, digital interface devices, remote temperature sensors, and those integrated ICs with thermostat functions.Figure 7. IC Sensors (Thermometer)Analog output devices (usually output voltage, but some also output current) are most like passive solutions when they need an ADC to process the output signal. Digital interface devices most often use a two-wire interface (I2C or PMBus) and have a built-in ADC. In addition to including a local temperature sensor, remote temperature sensors also have one or more inputs to monitor the remote diode temperature—they are most often placed in highly integrated digital ICs (for example, processors or field programmable gate arrays FPGA). When reached the temperature threshold, the thermostat can provide a simple alarm.Here are the details of two common types:🔺Analog Output Temperature SensorThe integrated sensor is made using silicon semiconductor integration process, so it is also called a silicon sensor or a monolithic integrated temperature sensor. It is a dedicated IC that integrates a temperature sensor on a chip and can take temperature measurement and then output analog signals. The main features of this sensor are single function (only measuring temperature), small temperature measurement error, low price, fast response speed, long transmission distance, small size, micro power consumption, etc., which are suitable for long-distance temperature measurement, control and measurement. What’s more, non-linear calibration doesn’t required, and the peripheral circuit is simple.🔺Digital Output SensorDigital temperature sensor is the product of microelectronics technology, computer technology and automatic test technology (ATE). The intelligent temperature sensor contains temperature sensor, A/D converter, signal processor, memory (or register) and interface circuit. Some products also come with multiplexers, central controller, random access memory and read-only memory. The characteristic of the intelligent temperature sensor is that it can output temperature data and related temperature control quantities, adapts to various microcontrollers (MCU). It realizes the test function through software on the basis of hardware, and its intelligent harmony also depends the level of software development.1.5 Temperature Sensor Cons and Pros🔺Table 2: Advantages and Disadvantages of thermocouples, RTDs, thermistors and IC sensors.CriteriaThermocoupleRTDThermistorIC SensorTemperature-250℃ to +750℃-100℃ to +500℃-267℃ to +2316℃-55℃ to +200℃AccuracyBestDepends on calibrationGoodGoodLinearityGoodWorstGoodBestSensitivityLessBestWorstGoodCircuityComplexDepends on accuracy/power requirementsComplexSimplestPower ConsumptionHigh when takingLow-highLowest Ⅱ How to Test: Measuring Indexes1) Measurement accuracy: 0.01 level2) Resolution 0.1uV and 0.1mΩ3) Scan switch parasitic potential: ≤0.4μV4) Temperature range: Water tank: (room temperature +5~95)°C; Oil tank: (95 ~ 300)°C; Low & constant temperature bath: (-80 ~ 100)°C; High temperature furnace: (300~1200)°C5) Temperature control stability: better than 0.01℃/10min (oil tank, water tank, low temperature constant temperature tank); 0.2℃/min (tube type verification furnace)6) Total uncertainty: For thermocouple verification, measurement uncertainty is better than 0.7 ℃, repeatability error <0.25 ℃; For thermistor verification, measurement uncertainty is better than 50 mk, repeatability error <10 mk7) Working power supply: AC220V±10%, 50Hz, and well protected grounding.8) High temperature furnace power: about 2kW9) Constant temperature bath power: about 2kW10) Power of microcomputer measurement and control system: <500 Ⅲ FAQ1. What is temperature sensor and how it works?How do temperature sensors work? They are devices to measure temperature readings through electrical signals. The sensor is made up of two metals, which generate electrical voltage or resistance once it notices a change in temperature. ... Temperature is the most common physical measurement type in industrial applications. 2. What happens when a temperature sensor goes bad?If the coolant temperature sensor goes bad it can send a false signal to the computer and throw off the fuel and timing calculations. ... This will cause the computer to think the engine is cold, even when it is not, and as a result will use more fuel than necessary. 3. Which temperature sensor is best?The most well-known are Pt100 (with a resistance of 100 ohms at 0°C) and Pt1000 (with a resistance of 1,000 ohms at 0°C). The Pt1000 offers better accuracy and a larger tolerance to long wire lengths than the Pt100. Compared to thermocouples, resistance sensors offer better accuracy and a more linear response. 4. What is the application of temperature sensor?Within our homes, temperature sensors are used in many electrical appliances, from our refrigerators and freezers to help regulate and maintain cold temperatures as well as within stoves and ovens to ensure that they heat to the required levels for cooking, air confectioners/heaters. 5. How do I know if my temperature sensor is bad?What Signs May Signal Your Coolant Temperature Sensor May Be Failing.Poor Fuel Economy.Irregular Temperature Readings.Black Smoke from Your Exhaust.Your Engine is Overheating.Your Check Engine Light is On. 6. How important sensors are nowadays?Intelligent sensor systems are omnipresent in our everyday lives. They provide security, save lives and improve our quality of life. As more and more areas of life are automated and networked, the importance of innovative sensor technologies will also increase in the future. 7. What should I consider when choose a temperature sensor?Several factors must be considered when selecting the type of sensor to be used in a specific application: temperature range, accuracy, response time, stability, linearity, and sensitivity. 8. What is the value range of a temperature sensor?The effective operating range is -50 to 250 °C for glass encapsulated thermistors or 150°C for standard thermistors. 9. What are the pros and cons thermocouple?Advantages and disadvantages of thermocoupleAdvantages of thermocouple: Simple working principle, Short response time, Low price, Wide temperature ranges, Rugged construction, Self-powered, Small size.Disadvantages of thermocouple: Nonlinearity, Accuracy, Interference can cause errors. Old technology, Needs calibration, Corrosion. 10. What is difference between PT100 and RTD?There is no difference a PT100 is a version of a RTD (resistance temperature detector). What is an RTD? A resistance temperature detector, also known as an RTD or resistance thermometer, is a type of temperature sensor. ... A PT100 sensor is the most common type of Resistance Thermometer (RTD).

SummaryIf you have follow the informations of sensor,you will know that sensors are always in a state of rapid progress.Now I will state a few things to prove it in the following.Sensor,also called Transducer, is a kind of detection device,it can receive the measured information and then output them according to a certain rule or other needed form to meet the transport, handling,storage,recording,displaying and controlling of imformation,etc. Know more about it,you can read the article : Most Comprehensive Sicence Popularizing of Sensor (detection device) Researchers created quantum control technique for quantum sensorsAs we all known,there is a common problem that designers are harder to deal with quantum sensing devices. How,University of Sydney researchers have sloved this trouble associated with this super-sensitive tech. They have created quantum control techniques in collaboration with Johns Hopkins Applied Physics Laboratory and Dartmouth College. This development will allow next-gen ultra-sensitive sensors to identify small signals and reject unwanted background noise.By applying the right quantum controls to a qubit-based sensor,the team adjust its response in a way  that guarantees the best possible exclusion of the background clutter—that is, the other voices in the room. In order to obtain and analyze signals, measurement protocols are set in place. Over the years, these protocols have lagged behind the advancement of electronic devices. The disparity has led to a phenomenon known as “spectral leakage,” which occurs when quantum sensors return unclear results.What's more, the new control protocols have reduced spectral leakage by several orders of magnitude by using improved sensor hardware. All the approach is relevant to nearly any quantum sensing application and can also be applied to quantum computing as it provides a way help identify sources of hardware error.‘quantum control techniques' is a major advance in how to operate quantum sensors.  New sensors uses for effective control of enviroment pollutionEnviromental pollution issue are always paid great attention by human being as the development of all the world. A team from the Faculty of Physics of Lomonosov Moscow State University has suggested using porous silicon nanowire arrays in highly sensitive gas sensors which may be used both for effective control of environment pollution levels and for the monitoring of air composition in closed spaces,from classrooms to space stations.According to researchers, these devices will be able to detect the presence of toxic and non-toxic gas molecules in the air at room temperature.Each sensor consists of an array of 10 micron long organized silicon nanowires with diameters ranging from 100 to 200 nm. Each nanowire has porous crystalline structure. The size of silicon crystals and pores between them in individual nanowire, varies from three to five nanometers.ey can be obtained by means of a cheap method of metal-assisted chemical etching. It is based on selective chemical etching, i.e. partial removal of surface layer from a bulk crystalline silicon with the use of metal nanoparticles as a catalyst. Moreover, the procedure is quick—at least 100 elements can be produced in a lab within just one hour.Such porous nanowires have huge specific surface area due to which their physical and chemical properties are extremely sensitive to molecular environment. It was also found out that the obtained samples exhibited an effective photoluminescence in the red spectrum region at room temperature. What's important,this gas sensors based on porous nanowires both work at home temperatures and also are reusable, because the all observed effects were completely reversible. Military sensor systems collect accurate informationCollecting accurate user and environmental information such as enemy's location,survive shock, vibration, moisture plays an important role in military system. Deployment complaints about the platform aside, Lockheed Martin’s Electro-Optical Targeting System (EOTS) for the F-35 Lightning II is a high-performance, lightweight, multi-function sensing solution for precision air-to-air and air-to-surface targeting (Figure 4). Integrated into the aircraft fuselage with a rugged sapphire viewport, the device talks to the aircraft via a fiber-optic interface.Presented as the first sensor to combine forward-looking and infrared search along with track functionality, EOTS enables situational awareness and precision delivery of laser and GPS-guided weapons. Advanced EOTS, the next iteration, will incorporate enhancements and upgrades like short-wave infrared, high-definition television, and an infrared marker.Today’s military sensors must operate well on their own, and function as part of a combined-arms approach with an interlaced network of sensing, to detect threats of any nature from any direction. One such way to address this is with a battlefield awareness solution like 3D Advanced Warning System (3DAWS) from BAE Systems, which can provide universal threat detection to an aircrew with a layered countermeasure defense.The modular and expandable system can integrate with fixed- and rotary-wing aircraft and countermeasure systems, with the flexibility to work with existing radar or laser warning systems. The core of the 3DAWS suite is the passively-cued, semi-active radio frequency 3D Tracker element, which serves as an adjunct to current and future passive threat detection systems.