How and Why to Measure Water Level?
Water level is the change in elevation of a solution in a fixed volume that occurs per unit of time, measured in centimeters.
Principle of water level measurement
The basic principle of water level measurement is to determine the level height based on the position of the interface between the liquid and the air or other medium. In practice, water level measurement usually uses different water level sensor or measuring devices that utilize different physical principles to achieve the measurement of liquid level height.
How to measure water level?
1. Direct measurement method:
Float level meter: the level is measured by the float rising or falling with the level change. The simplest and oldest detection method with relatively low price. As it is mechanical detection, its detection accuracy is easily affected by buoyancy, and the repeatability is poor. It is not suitable for viscous or impurity-containing liquids, and it is easy to cause float blockage.
Lever type liquid level meter: using the principle of leverage to determine the liquid level by measuring the effect of liquid level change on the lever.
2. Indirect measurement method:
Pressure level sensor: by measuring the pressure of the liquid on the bottom or side walls of the container to deduce the liquid level.
Ultrasonic level sensor: emit ultrasonic waves and receive its reflected waves, through the time difference to calculate the liquid level height.
Radar Level sensor: Transmits microwave and receives its reflected wave, calculates the liquid level height by time difference.
Capacitance Level Gauge: determines the liquid level by measuring the effect of liquid on the capacitance of the capacitor.
Capacitance measurement mainly measures the height of liquid by detecting the change in capacitance value caused by the change in liquid level. It includes a variety of types, such as capacitance level meters that can output analog quantities, liquid level capacitance proximity switches, and capacitance proximity switches. Capacitance proximity switches can be mounted on the side of the vessel for non-contact detection.
Why measure the water level?
1. Flood monitoring
According to the principle of hydraulics, water level change reflects the interaction between water, and is an important parameter for determining the structure of waters and their functions. Understanding the pattern of water level change can be used to develop flood control measures, river management planning, reservoir scheduling program. Therefore, water level observation is an important data to study the river morphology, riverbed evolution, water and sand movement.
2. Transportation safety
Oil tanks are the most common containers for level measurement. Generally speaking, oil tanks are divided into two categories: trade tanks and intermediate tanks. Trade tank level, temperature, density, volume, mass must be frequently monitored and measured, and the requirements for accuracy are high. Intermediate tanks are usually monitored only for parameters such as liquid level, temperature and pressure. If the tank level measurement is not well controlled, pumping out or oil spillage can occur. Oil and gas separator liquid level is high or low, there will be accidents, seriously affect the production and safety of the equipment after the sequence.
3. Chemical research
In chemical processes, liquid level meters are used to detect and measure the level of liquid in reaction vessels. They can provide important data to ensure the control and monitoring of the reaction process. In addition, level meters can be used to monitor and control chemical feeds and discharges to ensure operational accuracy and safety.
4. Food Safety
In the food and beverage industry, level sensors are used to monitor and control the level of liquids to ensure the stability and quality of production and packaging processes. For example, level meters can be used to monitor the level of raw materials and dosages during the production process to ensure product consistency and quality.
