Pressure sensors are a common sensing element, widely used in many industrial processes. Due to their inherent nonlinearity and the influence of external measurement conditions, the sensor’s output characteristics are generally nonlinear, resulting in multiple errors. These error factors often exist simultaneously. However, temperature has the most significant impact. So, making temperature compensation of pressure sensors extremely important.
This post will provide a detailed introduction to the pressure sensors’ temperature compensation. I hope you will find it useful.
How Temperature Changes Affect Pressure Sensor Accuracy?
With fluctuating temperatures, the sensitivity and accuracy of pressure sensors may be affected.
Temperature changes cause the temperature coefficient of resistance of a pressure sensor to change. The sensitive element in a pressure sensor is typically a metal resistor. When the temperature rises, the resistance of the metal resistor changes. It will cause inaccurate measurement results of the pressure sensor.
Temperature changes influence the density of the sensor material. When the temperature rises, the density of the material usually decreases. This results in a change in the force exerted on the pressure sensor. This effect can also cause a reduced accuracy.
Furthermore, high temperatures can damage the internal structure of the pressure sensor. Long-term operation in high-temperature environments can cause thermal aging of the sensor’s internal structure. It leads to performance degradation or even failure.
Why Do Pressure Sensors Need Temperature Compensation?
For pressure sensors, changes in resistance caused by temperature changes at the measurement site are similar to changes in resistance when measuring strain. This change in resistance can cause temperature drift errors in the measurement results.
When a sensor is subject to external interference, its output often changes independently of its input. This change is called “temperature drift.” The main cause of drift is that the sensitive components of the measurement system are often susceptible to interference from external temperature, humidity, electromagnetic interference, and sensor conditioning circuitry.
The introduction of temperature error directly affects the accuracy of the measurement results. Specifically, it manifests as fluctuations in the output voltage at the static operating point of the pressure sensor due to changes in the measured medium’s temperature. Therefore, temperature compensation is necessary.
What is Pressure Sensor Temperature Compensation?
In pressure sensor components, when other conditions remain unchanged, the output signal will drift with temperature changes. Drift leads to inaccurate measurement results. To minimize this phenomenon, we employ Algorithms, circuits, or chips to correct the measurement data. The aim is to eliminate the effects of temperature fluctuations on the component’s output signal within a certain range. This method is called temperature compensation for pressure sensors.
The characteristics of most pressure sensors are related to the ambient temperature. In fact, the sensor’s operating environment experiences significant temperature fluctuations. This temperature fluctuation also causes significant heat output, which can lead to significant measurement errors. This, in turn, affects the static characteristics of the pressure sensor. So, design measures must be implemented to reduce or eliminate the measurement effects of temperature fluctuations.
Read More about: 7 Types of Pressure Sensors: Different Types, Working Principles, and Definitions
Temperature Compensation Range:
The temperature compensation range is determined by the sensor’s structure, material, and compensation method. A summary of the compensation ranges of different sensors by Sino-Inst years of experience is as follows:
| Sensor Type | Operating temperature range | Compensated temperature range | Applicable Scenarios |
| Piezoresistive (silicon-based) | -40°C ~ +125°C | -20°C ~ +85°C | Industrial, automotive, consumer electronics |
| Piezoelectric (ceramic/quartz) | -200°C ~ +300°C | -50°C ~ +150°C | High-temperature industrial, aerospace |
| Capacitive | -50°C ~ +150°C | -20°C ~ +85°C | Low-pressure measurement, medical equipment |
| Diffused silicon (oil-isolated) | -40°C ~ +150°C | -25°C ~ +105°C | Hydraulic systems, automotive powertrain |
| MEMS (micro) | -40°C ~ +85°C | 0°C ~ +70°C | Consumer electronics, IoT devices |
| Fiber optic | -200°C ~ +400°C | -100°C ~ +300°C | Harsh environments (e.g., oil wells, nuclear facilities) |
Pressure Sensor Temperature Compensation Method:
Temperature compensation is based on the changes in the properties of materials at different temperatures. For example, the performance of electronic components, such as resistors, capacitors, and inductors can vary with temperature. It leads to unstable circuit operation. Temperature compensation technology offsets this performance deviation caused by temperature changes by introducing temperature-dependent compensation elements or algorithms.
Currently, the following temperature compensation methods are used for pressure sensors:
Self-Compensation Method
First, the Single-Wire Self-Compensation Method is simple. This method uses the appropriate temperature coefficient and expansion coefficient of the grid wire to enable the pressure sensor to self-compensate for temperature changes. These improve sensor accuracy. This method is easy to manufacture and low-cost. However, it is only suitable for specific test specimen materials. And it has a narrow temperature compensation range.
Bridge Compensation Method: Bridge compensation is a commonly used temperature compensation method. It uses a strain gauge as one arm of the bridge and a compensation gauge made of the same material as the strain gauge as the other arm. This ensures that the compensation gauge and the strain gauge exhibit the same temperature variation pattern.
When temperature changes, the resistance of the two adjacent arms of the bridge changes simultaneously. However, because their variation patterns are the same, the bridge output is not affected. Then ic can achieve temperature compensation. A differential bridge uses two strain gauges of the same type with opposite strain directions. It can directly compensate for temperature errors. Bridge compensation is simple and feasible. And it can compensate for a wide temperature range for various test specimen materials.
Circuit Compensation
Circuit compensation is typically implemented by adding a temperature compensation circuit. When temperature changes cause the sensor’s output voltage to shift, the temperature compensation circuit adjusts its output accordingly. This counteracts the effect of temperature change on the sensor’s output voltage.
For example, when temperature changes cause the sensor’s output voltage to increase, the temperature compensation circuit’s equivalent resistance increases, restoring it to its original value. The reverse is also true. This approach improves measurement accuracy.
Hardware Compensation
Hardware compensation is primarily achieved by adding thermistors and leveling resistors. For example, a piezoresistive pressure sensor can be supplemented with a temperature sensor to monitor the ambient temperature. The thermistor adjusts the sensor’s output signal accordingly to compensate for temperature errors. Additionally, a dedicated ASIC can be designed. It realizes two functions: low power consumption and temperature compensation.
Algorithmic Compensation
Algorithmic compensation is the most complex method for temperature compensation. It uses a software algorithm to control the sensor’s output signal. It can also eliminate temperature errors. Common algorithms include least squares linear fitting, curve fitting, and neural network-based compensation. These algorithms create a mathematical model based on the sensor’s output data at different temperatures. The sensor uses this model to correct the actual measurement data to show the right data.
If you have any technical problems, please feel free to contact us. We would be happy to answer your questions.
Sino-Inst Featured Pressure Sensor with Temperature Compensation
How to Choose a Temperature Compensation Method?
There are various methods for temperature compensation of pressure transmitters. Your consideration should depend on factors. such as your budget, sensor type, and application scenario. The simplest method is to purchase a pressure sensor module or chip that already includes temperature compensation and signal conditioning. Simply insert the chip into the pressure sensor for temperature compensation.
If you need to deploy pressure sensors on a large scale and require temperature compensation, consider an integrated solution. While the unit price is slightly higher, it saves significant development time, labor, and testing equipment costs.
If your budget is limited and the accuracy requirements are not critical. You can choose an analog output sensor with hardware compensation. If your company has extremely high production volumes. And you have strict requirements on cost and performance. I recommend purchasing bare chips or basic sensors. And you can establish your own fully automated calibration line. The line uses software-based digital compensation to achieve the optimal balance between cost and performance.
Read More about: PT Compensation of Flow Measurement
What is pressure and temperature compensation?
Temperature and pressure compensation ensure the accuracy of instrument measurement data under specific conditions.
Since the temperature and pressure at the measurement site often differ from standard conditions. We need to compensate for the measurement results to reflect the actual conditions.
What is temperature compensation on a pressure gauge?
Ordinary pressure gauges do not have temperature compensation. Digital pressure gauges do. Temperature compensation aims to keep the result as close to the true value as possible within the compensation range.
In electronic components, when other conditions remain unchanged, their output signals will drift with temperature changes. To minimize this error, we use algorithms to correct the output results. It eliminates the effects of temperature changes on the component output signal within a certain range. This method is called temperature compensation for electronic components.
What is pressure compensation?
Pressure compensation is a widely used technology in industrial equipment. It is mainly used to automatically adjust system pressure. To ensure that the system operates within a stable pressure range.
Pressure compensation utilizes a specific device or mechanism to automatically adjust for changes in system pressure caused by some factors.
All in all, there are various temperature compensation methods for pressure sensors. Temperature compensation is generally required in extremely high or low temperature environments.
For specific temperature compensation methods, consult a professional technician or contact the supplier for recommendations. Due to Sino-Inst’s over 20 years of experience in pressure measurement, our professional technicians can provide you with free technical support. Contact us now.
