The Types Of Liquid Level Measuring Instruments
There are many types of liquid level measuring instruments. Only according to the process medium and its working conditions, combined with the working principle of the instrument, can the most suitable measuring instrument be selected. The types of commonly used level gauges are as follows:
1. Magnetic flap level gauge
The magnetic flap level gauge is also called the magnetic column level gauge. The structure is mainly designed and produced based on the principles of buoyancy and magnetic force with magnets.
The position of the float (referred to as the magnetic float) in the measured medium is affected by buoyancy. The change of liquid level causes the position of the magnetic float
The coupling effect of the static magnetic force between the magnetic float and the magnetic flip column (also called the magnetic flip plate) causes the magnetic flip column to flip a certain angle (magnetic
The outer surface of the turning column is coated with different colors) to reflect the liquid level in the container.
2. Magnetic float level gauge (level switch)
The structure of the magnetic float level gauge (liquid level switch) is mainly designed and produced based on the principle of buoyancy and static magnetic field.
Called float) The position in the measured medium is affected by buoyancy: the change of the liquid level causes the change of the position of the magnetic float. Floating
The function of the magnet and sensor (reed switch) changes the number of components (such as fixed-value resistors) connected in series to the circuit.
The electrical quantity of the meter circuit system is changed. That is, the change of the position of the magnetic float causes the change of the electrical quantity. through
The change in electrical quantity is detected to reflect the liquid level in the container.
3. Explosion-proof float level switch
The explosion-proof float level switch is also called the explosion-proof float level controller. A liquid level control instrument specially designed and manufactured for use in explosive environments. This product is designed based on the principle of buoyancy and leverage. When the liquid level in the container changes, the position of the float will change with the change of the liquid level. This displacement will act on the micro switch through the lever, and then the micro switch generates a switch signal.
4. Plate type transparent/reflexion glass level gauge
Working principle and structure
The liquid level gauge is designed based on the principle of the communicating device. The liquid passage composed of the reflexion gauge glass or flat gauge glass plate and the main body of the liquid level gauge is connected to the container to be measured by a flange or tapered pipe thread to form a communicating device. The liquid level and the liquid level can be observed through the glass plate. The liquid level in the container is the same as the liquid level. The needle valve at both ends of the level gauge not only functions as a stop valve, but the steel ball inside has the function of a check valve. When the level gauge is accidentally damaged and leaked, the steel ball can automatically close the liquid channel under the action of the medium pressure. Prevent a large amount of liquid from flowing out and play a role in safety maintenance. The level gauge can achieve anti-corrosion, heat preservation, anti-frost, lighting and other functions by changing the data of the parts or adding some auxiliary parts.
5. Glass tube level gauge
Working principle and structure
The liquid level gauge is a liquid channel composed of glass tubes designed based on the principle of a communicating device. The passage is connected with the container to be tested by a flange or a taper pipe thread through a connecting pipe to form a communicating device, and the liquid level is the same as the liquid level in the container when observed through the glass tube. Tubular level gauge is mainly composed of glass tube, maintenance sleeve, upper and lower valves and connecting flange (or thread). The level gauge can achieve the function of anti-corrosion or heat preservation by changing the information of the parts or adding some accessory parts.
6. Steel belt level gauge
The steel belt level gauge is a traditional level gauge. Designed and manufactured by the principle of mechanical balance, it is composed of a liquid level detection device, a high-precision displacement transmission system, a constant force device, a display device, a transmitter device and other peripherals.
7. Heavy hammer detection level gauge
The weight detection level gauge is designed and produced according to the principle of mechanical balance. When the steel belt is immersed in a liquid at a certain position, the weight of the float, the steel wire rope (or the steel belt) and the pointer are subjected to gravity, and the steel belt is subjected to the liquid The buoyancy and system friction are in equilibrium.
8. Ultrasonic level meter
The working principle of this product: is to transmit energy waves through a device that can emit energy waves (usually pulse signals). The energy waves are reflected by obstacles, and a receiving device receives the reflected signals. Determine the level change according to the time difference of the energy wave movement process. The microwave signal is processed by the electronic device, and finally converted into an electrical signal related to the level. A probe transmits an ultrasonic pulse signal to the surface of the measured medium. The ultrasonic wave is reflected when it encounters the measured medium (obstacle) during transmission. The reflected ultrasonic signal is detected by the electronic module and processed by special software to analyze the transmitted ultrasonic and return signals. The time difference of the wave, combined with the transmission speed of the ultrasonic wave, can accurately calculate the distance traveled by the ultrasonic wave, and then can reflect the situation of the level.
9. Intelligent radar level meter
Intelligent radar level meter is a microwave level meter, an application of microwave (radar) positioning technology. The energy wave is emitted through a device that can emit energy waves (usually pulse signals). The energy waves are reflected by obstacles, and a receiving device receives the reflected signals. Determine the level change according to the time difference of the energy wave movement process. The microwave signal is processed by the electronic device, and finally converted into an electrical signal related to the level.
10. Guided wave radar level gauge
Guided wave radar level gauge is a microwave level gauge, an application of microwave (radar) positioning technology. Transmit energy waves through a device that can transmit energy waves (usually pulse signals). The energy waves are transmitted in the waveguide, and the energy waves are reflected by obstacles. The reflected energy waves are transmitted to the receiving device by the waveguide, and then received by the receiving device Reflected signal. Determine the level change according to the time difference of the energy wave movement process. The microwave signal is processed by the electronic device and finally converted into an electrical signal related to the level.
11. Capacitive level meter
The measuring principle of the capacitive level meter is that the oscillation frequency of the oscillation circuit is related to the capacitance value. The change of the level causes the change of the system capacitance, which in turn changes the oscillation frequency of the oscillation circuit. The oscillating circuit in the sensor can convert the capacitance change caused by the level change into a frequency change, and send it to the electronic module. After the calculation, analysis and disposal, it is converted into the engineering quantity and displayed, thereby realizing the continuous measurement of the level.
12. Radio frequency admittance level controller
The radio frequency admittance level controller is a new type of level measuring instrument designed and manufactured using radio frequency admittance level control technology. The radio frequency admittance measurement technology is simply a method of using high frequency current measurement system admittance. Point-to-point radio frequency admittance technology is different from capacitive technology. It uses three-terminal technology to diversify the measurement parameters. The radio frequency admittance technology introduces measurement parameters other than capacitance, especially resistance parameters, which improves the signal-to-noise ratio of the measurement signal of the instrument, thereby greatly improving the resolution, accuracy and reliability of the instrument; the diversity of measurement parameters also Vigorously expand the reliable application field of the instrument. The level control technology that makes the product anti-hanging material (material to which the sensor adheres is called hanging material) has better performance, more reliable work, more accurate measurement, and wider applicability.
13. Tuning fork level controller
The tuning fork level controller is a new type of level switch. The induction rod base of the tuning fork level switch is designed and manufactured using the principle of tuning fork vibration. The tuning fork rod is driven by a piezoelectric chip, and the vibration signal is received by another piezoelectric chip, so that the vibration signal is circulated and the induction rod resonates. When the material is in contact with the sensor rod, the vibration signal gradually becomes smaller, until the resonance stops, the control circuit will output the electrical contact signal. Due to the natural principle that the sensitivity of the sensor rod gradually weakens from the front to the rear seat, no error signal will occur when the material in the tank and the surroundings of the barrel accumulate and touch the sensor rod base (rear) or discharge.
14. Magnetostrictive level gauge
The working principle of the magnetostrictive liquid level sensor: an initial pulse is generated by the electronic circuit in the electronic warehouse. When this initial pulse is transmitted in the waveguide wire, a rotating magnetic field that advances in the direction of the waveguide wire occurs at the same time. When the permanent magnetic field in the ring or floating ball meets, a magnetostrictive effect occurs, which causes the waveguide wire to twist. This twist is sensed by the energy pickup mechanism installed in the electronic warehouse and converted into a corresponding current pulse. The circuit calculates the time difference between the two pulses, and then the measured displacement and liquid level can be accurately measured.