Water level indicators are widely used in daily life and industrial scenes, and their accuracy and stability directly affect the normal operation of the equipment. The application of pressure sensors in liquid level measurement provides a more efficient and reliable solution to the traditional measurement method. However, the use of pressure sensors as core components often leads to the following problems:
- Is the accuracy of the pressure sensor sufficient for level measurement?
- How to install the pressure sensor to ensure the stability of the measurement?
- Do I need to calibrate the pressure sensor periodically for long-term use?
Let’s start understanding!
Catalog
What is Pressure Sensor？
Pressure sensor is a device that converts a pressure signal into a measurable electrical signal. In water level indicator applications, the sensor calculates the corresponding level height by detecting changes in liquid pressure. This method is favored for its simple structure and easy installation.
Working Principle of Pressure Sensor:
Pressure sensors sense changes in external pressure through internal sensitive elements, such as piezoresistive chips or capacitive structures, and convert them into linear voltage signals. The pressure of the liquid is linearly related to its depth, so by detecting the pressure can accurately reflect the liquid level.
Why select pressure sensor:
- High accuracy: the measurement error of pressure sensors can usually be controlled within ± 0.5%, suitable for most water level measurement scenarios.
- Durability: Many industrial-grade pressure sensors are housed in stainless steel, which is highly resistant to corrosion and suitable for long-term use.
- Lower cost: Compared to other level measurement methods (e.g., ultrasonic or radar level gauges), the overall cost of pressure sensors is more favorable.
Pressure Sensor Application Scenarios in Water Level Indicators
Household water tank level detection
In household water tanks, pressure sensors are used to measure water pressure changes at the bottom of the tank to get a real-time view of the water level. Such applications require less accuracy, but need to ensure that the sensor is waterproof.
Industrial Tank Level Monitoring
In industrial production, the level of chemical or fuel storage tanks needs to be accurately monitored. The use of pressure sensors allows real-time transmission of liquid level data and remote monitoring through industrial control systems, greatly improving work efficiency.
Agricultural irrigation systems
In agricultural irrigation, water storage is often used in conjunction with level indicators for efficient water use. Pressure sensors are the preferred solution for irrigation systems due to their low power consumption and cost-effective features.
Key Points for Pressure Sensor Installation
The pressure sensor in the water level indicator is not mounted in a flanged, threaded or suspended manner, but is mounted directly on the PCB by soldering. This design has the following advantages:
- Improved reliability: The solder mounting method reduces the interference of external vibration on the measurement accuracy.
- Reduced cost: No additional fixing parts are required, reducing installation costs.
- Ease of maintenance: PCB mounting makes it easy to replace or repair the sensor at a later stage.
About Calibration
In most application scenarios, the pressure sensor has been initially calibrated at the factory and no additional adjustments are required by the user. However, if used in high-precision scenarios, it is recommended that the zero point and range be reviewed periodically to ensure long-term measurement stability.
FAQ
① How to select the range of the pressure sensor?
The range of the sensor should be selected according to the maximum height of the water level. For example, for a tank with a maximum depth of 4 meters, it is recommended to select a pressure sensor with a range of 0~40kPa.
② Will impurities in the water affect the measurement?
Generally speaking, impurities in the water do not directly affect the measurement accuracy of the pressure sensor. However, it is recommended to clean the detection port of the sensor regularly to avoid blockage that affects data stability.
③ Can the pressure sensor be replaced by other means?
Ultrasonic level gauges or capacitive level sensors can be used as alternatives, but their cost and complexity are usually higher than that of pressure sensors, and they have higher requirements for the installation environment.
Conclusion
The application of pressure sensors in water level indicators has become the preferred solution for level measurement by virtue of its efficiency, accuracy and low cost. In actual use, the service life and measurement stability of the sensor can be significantly improved through proper installation and maintenance.
