Outside Mounted
Ultrasonic Liquid Level Gauge Measurement Program
Technology
Technology
Description
Laoshan City, Xintai Weighing Instrument Co.Ltd.
One, the foreword
Laoshan City, Xintai Weighing Instrument Co. Member unit of China Weighing Instrument Association. It is located in Lushan City, a national model city for environmental protection, which is the easternmost part of Shandong Peninsula with beautiful scenery.
The company covers an area of more than 20,000 square meters, since its establishment, the company has been committed to the field of weighing and measurement of computer control technology, automated process control equipment and high-precision weighing control system research and development, manufacturing and sales, according to the user and the market needs to design and manufacture a variety of special systems and products.
The company is engaged in the design, development, production and sales of weighing and metering of SCS series digital electronic vehicle scales, electronic weighing scales, liquid intelligent filling system, weighing method level meter, external ultrasonic level meter, quantitative packaging system, etc. It is a high and new tech enterprise which provides metering and management programs and develops metering management system for various large and medium-sized industrial and mining enterprises.
The company developed the liquid chlorine cylinder intelligent filling system, in the ionic membrane (diaphragm) caustic soda industry is widely used. It has become a professional manufacturer of liquid chlorine filling and management equipments with the highest safety performance (all equipments' protection level reaches IP65), the most advanced technology, the most superior performance, and the most complete supporting equipments.
The company develops two kinds of liquid level meter: weighing method liquid level meter; (the display instrument shows both the weight of the tank and the analog percentage of liquid level) external ultrasonic liquid level meter.
Because of not opening holes in the tank, high precision measurement, safety and easy maintenance, it has become the preferred liquid level meter for toxic, strong acid, strong alkali and other chemical enterprises.
The company in line with the "people-oriented, science and technology, reputation first" business philosophy, relying on ISO9001: 2008 quality management system, the production process and product quality under strict control, access to the People's Republic of China *** and the country to manufacture measuring instruments license (LU system 00000374), Repair of measuring instruments license (Lu repair 10000002) and measurement of qualified confirmation certificate.
The company has advanced weighing production technology, work equipment and precision testing instruments, the products strictly implement the national standards of GB/T 7723-2008 and GB/T 335-2002, and have been strictly tested by Shandong Province Quality and Technical Supervision Bureau, Shandong Province Measurement and Research Institute, and Weihai City, Shandong Province Quality and Technical Supervision Bureau, and the indexes are all qualified.
We will make unremitting efforts, pioneering and innovative, with high-quality products, favorable prices, perfect service will be more and better products to domestic and foreign markets. We are willing to provide quality service for every customer and do our best for your career development. May we work hand in hand, heart and hand in hand, *** with towards a better tomorrow!
System Description
1, Overview
Outside the ultrasonic level meter, is a new technology developed by the company, new products, level measurement using the sensor outside the sensor, and the measured liquid non-contact measurement, is a major innovation in the history of liquid level measurement.
Outside the ultrasonic level meter, can be outside the tank continuous measurement of liquid level, the tank does not open the hole, the installation can not stop production, especially suitable for toxic substances, strong acid, strong alkali and pure liquid tank level for accurate measurement, the instrument adopts the explosion-proof design, but also in the need for explosion-proof occasions.
2, the working principle
Outside the ultrasonic level meter uses the radar echo ranging principle, combined with the company's digital signal processing technology, to overcome the influence of the tank wall, high precision non-contact measurement of the level of liquid in the tank. The instrument takes the special ultrasonic processing technology independently developed by our company as the system kernel, realizing the ultra-high-speed digital signal processing function. The processed liquid level is accurate and does not need CPU to analyze, compare and judge the liquid level, after CPU obtains the liquid level value, it can be sent to NVRAM for storage and to digital monitor for display. In addition, the instrument can output 4～20mA standard signal or output the measurement result to the upper computer (or secondary meter) through RS-485 interface.
3, product features
● Non-contact measurement: the most ideal measurement in industrial instrumentation
● High accuracy, responsive
● Wide range of applications: can be used for highly toxic, corrosive, high-pressure, a variety of complex conditions, as well as a variety of explosive gas environment of the measurement of the liquid medium
● Easy to install, Simple operation
● Installation without stopping production, no tanks, no fire
● Instrumentation does not require regular calibration
● Instrumentation is reliable and stable
● Instrumentation does not require user maintenance, maintenance-free
● Long service life
● Intelligent, electronic instrumentation
● Strong anti-jamming ability
● The instrument can be used for a variety of liquid media measurements in highly toxic, corrosive, high pressure, complex conditions and explosive gas environments
4.
4, technical parameters
4.1 performance
● range specifications: 3m, 5m, 10m, 20m, 30m
● display resolution: 1mm
● short-term repeatability: 1mm
● Measurement error: 1 ‰ (the tank wall is too thick, the pressure and temperature may affect the accuracy of the stability)
● Migration: ±10 m
● Liquid crystal display: 6-bit LCD
4.2 Power supply
● 24V DC, ±15%,10W
4.3 Wiring form
● 4-wire system (two power lines, two signal lines)
4.4 Interface
● Analog output: 4-20mA Maximum load 750Ω
● Communication interface: RS-485 4.5 Shell
● Structure: cast aluminum
● Protection level: IP65
● Explosion-proof mark: ExdIICT6
4.5 Environmental conditions
● The main body of the use of the ambient temperature: -20 ℃ ~ +70 ℃
● Ultrasonic probe ambient temperature:-50℃～+100℃
● Humidity:15%～100% RH Note: If the temperature is lower than -20℃, it is recommended to add thermal insulation measures to the host computer (add thermal insulation or heat tracing device):
5, application conditions
5.1 Medium purity
● Liquid can not be filled with dense air bubbles.
● Liquid can not be suspended in a large number of solids, such as crystalline material.
● The liquid must not contain large amounts of sediment.
5.2 Medium Viscosity
● Dynamic Viscosity <10mPaoS. 10mpaS <Dynamic Viscosity <30mPaS may reduce the range of the instrument. Power viscosity>30mPaS can not be measured. Note: with the temperature increase viscosity decrease, most of the high viscosity of the liquid by the temperature effect is more obvious, so in the measurement of viscous liquid should pay attention to the liquid temperature effect.
5.3 Measured vessel
● Material: The wall of the vessel where the measuring probe is installed is required to be made of hard material that can transmit the signal well. Examples: carbon steel, stainless steel, various hard metals, fiberglass, epoxy resin, hard plastics, ceramics, glass, hard rubber and other materials or their composite materials. If the vessel wall where the measuring probe is mounted is made of multi-layer materials, the layers should be in close contact with each other without air bubbles or gas entrapment, and the inner and outer surfaces of the vessel wall should be flat. Examples: vulcanized hard rubber liner, epoxy resin liner, stainless steel liner, titanium liner.
● Wall thickness: 2～70mm
● Tank type: Ball tank, horizontal tank, tank, vertical tank, etc.
5.4 Probe Installation Requirements
● For iron containers, the probe can be coated with silicone grease on the working end surface and directly affixed to the bottom of the container with a magnetic suction cup; if the container shell is glass and other materials, you can glue the probe fixed or fixed to the bottom of the container with a bracket. The probe must point to the same straight line with the measured distance.
● The probe is not directly above the coils and other obstructions;
● Far from the tank bottom inlet to avoid the impact of the inlet liquid flow on the measurement;
● Far from the top of the tank below the inlet to avoid the inlet liquid shock to make the liquid level fluctuate violently affect the measurement;
● Higher than the liquid outlet or sewage outlets to avoid the tank bottom of the long-term deposition of dirt on the measurement of the adverse impact of.
● level measuring head with magnetic or welding/bonding fixing method of installation, the vessel wall mounting surface size should be not less than Ф100mm round surface, the surface roughness should be up to 1.6, the inclination should be less than 3 ° (except for the bypass pipe).
6, order selection
A non-explosion-proof
B explosion-proof
Range:
3 meters range
5 meters range
10 meters range
20 meters range
30 meters range
Probe Selection
Ordinary (Single probe: Self-calibrating type (dual probes: ultrasonic transducer)
7. Field Installation and Physical Drawing
8. Installation
● Normal Type (Single Probe) Installation Schematic
● Self-calibrating Type (Dual Probe) Installation Schematic
The calibration probes provide the temperature and pressure compensation for the measuring probes, which enables the main probe to make timely and accurate measurements. The calibration probes provide temperature and pressure compensation for the measuring probes so that the main probes can correct the measurement errors due to temperature and pressure in time and accurately during the measurement, which ensures the instrument's high-precision liquid level measurement in complex environments. The calibration probe can be installed in several ways:
● ① Ball tanks, horizontal tanks, vertical tanks in the direction of the diameter of the position;
● ② The bottom of the calibration plate has been processed;
● ③ Larger diameter and connected to the tank with a liquid-filled pipe or blind pipe. For example: liquid-filled discharge pipe, feed pipe. However, the wall thickness of 8mm pipe, the diameter of the distance needs to be more than 0.15m; wall thickness of 10mm pipe, the diameter needs to be more than 0.2m; wall thickness of 15mm pipe, the diameter of 0.25m or more; and so on.
Note: Selection or specific installation program please agree with the manufacturer.
9 Installation Guide
9.1 Installation of Instrument Box
9.1.1 Installation Schematic of Instrument Box
9.1 .2 Installation Requirements of Instrument Box
0 The instrument box should be installed in the shade, back to sunlight, because the display of the mainframe of the liquid level meter can not be subjected to sunlight for a long period of time;
1 Used for areas with relatively low temperature (temperature below -20℃), it is recommended to increase the heat preservation measures (add insulation layer or heat tracing device to the instrument box) to prevent the temperature from being too low to affect the use of the liquid level meter;
2 The standard length of the instrument probe wire is 8 meters, so pay attention to ensure that the appropriate distance between the instrument box and the probe position;
3 There are 4 holes on the base of the instrument box, which can be fixed on the ground by expansion bolts (impact drilling). It can be fixed on the ground by expansion bolts (use M12 drill bit for impact drill); the user can decide according to the work site.
9.2.2 Ultrasonic Probe Installation
9.2.1 General Installation Requirements
* For the ferromagnetic material of the container, magnetic suction cups can be directly adsorbed on the bottom of the container can be, as shown in Figure 2-A, if the container shell is glass, stainless steel and other materials, you can use the adhesive or bracket fixing and other ways of the probe will be installed on the bottom of the container, as shown in Figure 2-B.
* The probe can be installed on the bottom of the container by using the magnetic suction cup;
* The bottom of the container selected installation location to deal with flat, clean; grinding treatment of the container wall should be sprayed with anti-rust paint, to avoid the probe and the container wall contact rust affects the measurement;
* When installing the probe sensing surface and the mounting surface coated with coupling agent (vacuum silicone grease) to ensure that ultrasonic signals are well propagated;
* Probe pointing to the measured distance in the same In a straight line;
* probe directly in front of the stirring device or coil and other obstructions;
* avoid the lower inlet, in order to avoid the inlet liquid flow on the measurement of the impact;
* avoid the upper inlet position, in order to avoid the inlet liquid shock to make the liquid level fluctuations affect the measurement;
* avoid the outlet or sewage outlets; if the conditions are not met, there should be measures to ensure that the regular removal of sediment at the bottom of the tank. Measures to ensure that the bottom of the regular removal of sediments;
* The size of the installation surface on the wall of the container should not be less than Ф100mm round surface, the surface roughness should be 1.6, the inclination should be less than 3 ° (except for the bypass pipe);
Figure 2-A Figure 2-B
9.2.2 Specific Requirements and Schematic Diagrams
A Horizontal Tank Installation requirements and diagrams
A Horizontal tanks and the installation requirements and schematic
The principle of liquid level meter probe installation position selection is: probe as far as possible away from the inlet and outlet (especially away from the inlet, the farther the better);
* Ordinary type is a single-probe measurement (measuring probe is installed at the bottom of the tank); self-calibrating type is a double-probe measurement (measuring probe is installed at the bottom of the tank, the calibrating probe is installed in the direction of the diameter of the tank);
* The level meter's measuring probe should be installed at the bottom of the tank as far as possible. Measuring probe should be installed at the lowest point of the tank as far as possible; the calibration probe of the liquid level meter should be installed at the center of the tank diameter direction (both should not be in a straight line);
* If there is an insulating layer on the outer surface of the tank, there should be space for the installation of the probe; the size of the insulating layer should be not less than 200x200mm;
* The length of the probe line of the liquid level meter is 8 meters; therefore, it should be ensured that the probe and the instrument box should be separated from each other. Ensure that the distance between the probe and the instrumentation box is appropriate;
B Ball tank installation requirements and schematic diagram
* Liquid level meter probe installation location selection principle: probe as far away as possible from the inlet and outlet (in particular, away from the inlet, the further the better);
* Ordinary type is a single-probe measurement (measuring probe is installed at the bottom of the tank); self-calibrating type is a two-probe measurement (measuring probe is installed at the bottom of the tank); self-calibrating type is a two-probe measurement (measuring probe is installed at the bottom of the tank). The measuring probe is installed at the bottom of the tank, and the calibration probe is installed at the direction of the tank equator);
* The measuring probe of the liquid level meter should be installed at the bottom of the tank near the manhole; the calibration probe of the liquid level meter should be installed at the equator of the spherical tank (close to the rotary ladder);
* If there is a heat preservation layer on the outer surface of the tank, the space should be reserved for the installation of probes; the size of the heat preservation layer should not be less than 200x200mm;
C Vertical tank installation requirements and schematic diagram
* Installation of liquid level meter in vertical tank, the base is generally cement base; please reserve space for probe installation in the base (recommended size of 200x200mm);
* Principle of the liquid level meter probe installation location selection: probe as far as possible away from the inlet and outlet (especially away from the inlet, the farther the better);
* Liquid level meter probe installation location selection principle: probe as far as possible away from the inlet and outlet (especially away from the inlet, the farther the better). The farther away from the liquid inlet, the better);
* Ordinary type is single probe measurement (measuring probe is installed at the bottom of the tank); self-calibrating type is double probe measurement (measuring probe is installed at the bottom of the tank, calibrating probe is installed on the side wall of the tank); the height of the calibration probe from the ground should be in the range of 0.5 to 1 meter;
10 external dimensions
10.1 Liquid Level Gauge Mainframe
10.2 Liquid Level Meter Probe and Suction Cup
11, external level meter features
11.1 and other types of liquid level meter performance comparison
Serial No. Instrument Type Main Features Disadvantages Installation Mode Price
1 ultrasonic liquid level meter Not in direct contact with the media, only contact with the gas-phase part of the accuracy is relatively low, can not be measured in the pressure vessel, can not be measured Volatile medium Top mounted, the equipment needs to open the hole Medium
2 RF Conductivity Level Gauge can measure the interface is not easy to calibrate, the measurement medium can not be sticky, otherwise the probe hanging material affects the measurement accuracy Medium
3 Magnetic Flip Level Gauge Intuitive, easy to install Magnetic ball is easy to be jammed, resulting in failure to indicate the remote transmission Connected with the equipment, the need to open the hole Low
4 Differential Pressure Level Gauge Popular range
4 Differential Pressure Level Gauge Popular, easy to calibrate, close contact with the density of the medium, corrosive media, the measurement of the instrument membrane box material requirements of the instrument is very high equipment needs to be open hole Medium-low
5 γ-ray level meter Non-contact measurement with the medium, high accuracy, high precision, nuclear radiation harm to the human body, does not apply to large-diameter containers, equipment does not need to be opened Higher
6 Float Level Gauge and the medium in direct contact, the float sealing requirements to be strict, can not be used for the equipment
6 Float Level Gauge and the direct contact, the float sealing requirements to be strict. Float sealing requirements to be strict, can not measure viscous media equipment top hole low
7 external level meter completely non-contact measurement, can be used in harsh environments, easy to install, easy to maintain the medium viscosity & lt; 30mpa.s, the medium can not contain a large number of air bubbles equipment does not need to open the hole Medium
11.2 The use of the external level meter
Applicability Factors Specific requirements
Liquid viscosity Dynamic viscosity <30mpa.s
Liquid purity Cannot suspend a large number of solids and deposit a large amount of sediment, can not have a large number of air bubbles
Liquid temperature Zero -50 ° C to 250 ° C
Vessel material Can be able to well transfer the vibration of the hard material, such as carbon steel, stainless steel, glass fiber reinforced plastic, Epoxy resin, aluminum, etc.
Vessel wall interlayer or liner No soft liner or gas interlayer, such as multi-layer materials, the layers should be in close contact with each other, no air bubbles, and the inner and outer surfaces of the vessel wall should be flat
Vessel shape Ball tanks, vertical tanks, horizontal
Vessel structure If there is an agitator in the vessel, it is necessary to add anti-wave tube, steering tube
Vessel pressure has no effect on the measurement
Vessel pressure No effect on the measurement
Probe installation location There should be a space of 300mm*300mm*200mm at the bottom of the tank
Minimum level 200mm
Maximum measurement level 30m
Ambient temperature 0 to 95℃
Explosion-proof requirement ExdⅡBT6 explosion-proof
11.3 The medium of the external liquid level gauge can be Measuring medium
Propylene Liquefied petroleum gas Liquid chlorine Ethylene
Liquid ammonia Liquid hydrogen chloride n-butane Propane
Butadiene Butane Butene Hydrogen sulfide
Pentane Isobutene Hydrogen fluoride Methanol
Gasoline Ammonia Acetone Diesel fuel
Glycol Ethanol Liquid alkali Trichloroethylene
Kerosene o-xylene Ethyl ether Acidic water
11.4 Superiority of External Level Gauge Compared with Other Types of Level Gauges
The greatest superiority is reflected in the environmental protection and safety, external level gauge is simple to operate, easy to maintain, intelligent and environmentally friendly.
Anti-electrical interference is very strong, for the tank motor vibration, into the liquid impact and other kinds of interference do not affect the instrument measurement.
External liquid level meter with communication function, easy to connect with the Internet, connect with the printer, realize the management modernization.
11.5 External Level Gauge Benefits
From the amount of instrumentation maintenance greatly reduces the burden, do not have to worry about the accuracy of the instrument; do not have to worry about the leakage of the medium due to instrumentation, triggering safety accidents, and even cause the system to stop; easy to install, easy to maintain, easy to operate, you only need to check the sealing oil of the probe at regular intervals.
11.6 Intelligent external level meter development trend
Liquid chlorine, vinyl chloride, propylene, liquefied petroleum gas and other different media and industries, all types of level meter application ratio and market share varies, but with the strengthening of people's awareness of environmental protection, the economy soaring development, this intelligent external level meter will be more and more favored by the people, especially in volatile, Toxic and hazardous media tanks more to show its superiority, the near future external level meter will become a leader in the ranks of environmental protection instrumentation, while the realization of network control, it will become a new type of industrial control networks in the development of instrumentation leader.