Ultrasonic liquid level gauge is a non-contact continuous liquid level measuring instrument controlled by microprocessor.Simple installation, convenient measurement, not affected by liquid viscosity and density.It is widely used in liquid level measurement due to its absence of mechanical moving parts, higher reliability and less maintenance.However, the measurement accuracy is relatively low, and there is a blind area in the measurement, so it cannot be measured in a pressure vessel, nor can it be used to measure volatile media.It is precisely because of the limitations of the ultrasonic level gauge itself that if no attention is paid during use, some failures are prone to occur.In order to help users use the ultrasonic liquid level gauge better, this article focuses on the working principle and failure causes of the ultrasonic liquid level gauge.1. Measuring principle of ultrasonic liquid level gauge In the measurement of ultrasonic liquid level gauge, the ultrasonic pulse is sent by the sensor (transducer), and after being reflected by the surface of the object, it is received by the same sensor (transducer) and converted into an electrical signal .sensor (pass
What is a liquid level gauge: The height of the liquid medium in the container is called the liquid level, and the instrument for measuring the liquid level is called a liquid level gauge.The liquid level gauge is a kind of level instrument.The good structure and installation method of the level gauge can be applied to high temperature, high pressure, strong corrosion, easy crystallization, anti-blocking, anti-freezing and solid powdery and granular materials.It can measure the liquid level of strong corrosive medium, the liquid level of high temperature medium, and the liquid level of sealed container, which has nothing to do with the viscosity, density and working pressure of the medium.First, the selection of radar level gauges All kinds of liquid level instruments have their own characteristics and advantages. When selecting instruments for measuring media, various factors should be considered comprehensively, including the characteristics of the measured medium, medium measurement purpose and other factors such as environmental and economic conditions.Try to maximize the strengths and avoid weaknesses among many instruments, and choose the instrument suitable for the measurement medium and purpose.2. Consider the characteristics of the measured medium. Since there are many types of radar level gauges, before measuring, the first thing to do is to
The working principle and selection of radar level gauge 1. The working principle of radar level gauge The radar level gauge uses ultra-high frequency electromagnetic waves to emit through the antenna to the liquid surface of the detected container. When the electromagnetic waves hit the liquid surface and reflect back, The instrument detects the time difference between the launch wave and the echo, thereby calculating the height of the liquid surface.The better the conductivity of the measured medium or the greater the dielectric constant, the better the reflection effect of the echo signal.The radar level gauge is mainly composed of a transmitting and receiving device, a signal processor, an antenna, an operation panel, and a display.Transmit-reflect-receive is the basic working principle of radar level gauge.It is divided into time difference and frequency difference.The time-of-flight type is that the emission frequency is fixed, and the height of the measured liquid level is measured by measuring the running time of the emission wave and the reflection wave, and through an intelligent signal processor.The relationship between the running time of this type of radar level gauge and the distance of the liquid level is: t=2d/c.In the formula, C is the propagation speed of electromagnetic wave, C=300000km/s
Ultrasonic liquid level gauge is a non-contact continuous liquid level measuring instrument controlled by microprocessor.Simple installation, convenient measurement, not affected by liquid viscosity and density.It is widely used in liquid level measurement due to its absence of mechanical moving parts, higher reliability and less maintenance.However, the measurement accuracy is relatively low, and there is a blind area in the measurement, so it cannot be measured in a pressure vessel, nor can it be used to measure volatile media.It is precisely because of the limitations of the ultrasonic level gauge itself that if no attention is paid during use, some failures are prone to occur.In order to help users use the ultrasonic liquid level gauge better, this article focuses on the working principle and failure causes of the ultrasonic liquid level gauge.1. Measuring principle of ultrasonic liquid level gauge In the measurement of ultrasonic liquid level gauge, the ultrasonic pulse is sent by the sensor (transducer), and after being reflected by the surface of the object, it is received by the same sensor (transducer) and converted into an electrical signal .sensor (pass
Primary treatment: The primary treatment system is also called the physical treatment system, which mainly removes the suspended solid pollutants in the sewage. Most of the physical treatment methods can only meet the requirements of the primary treatment.After primary treatment, BOD can generally be removed by about 30%, which does not meet the discharge standard.Primary treatment belongs to the pretreatment of secondary treatment.Coarse grille: The purpose of coarse grille is to remove coarse suspended solids that may block the pump unit and pipeline valves, and to ensure the normal operation of subsequent treatment facilities.Coarse grille is composed of a group (or groups) of parallel metal grid bars and frames, installed obliquely on the water inlet channel, or at the inlet of the water collection well of the water inlet pumping station, to intercept coarse suspended matter and Impurities.Grit chamber: It is inevitable that sewage will be mixed with mud and sand in the process of migration, flow and collection.If the sand in the sewage is not pre-sedimented and separated, it will affect the operation of the subsequent treatment equipment.The grit chamber is mainly used to remove
This article is aimed at the analysis of the production process of a large-scale chemical enterprise producing 100,000 tons of chlor-alkali. The chemical plant has long used the tank position calculation method to measure the production of light and concentrated alkali, because the cross-section of the storage tank is large and the scales are divided The accuracy of the accuracy is poor, resulting in the accuracy of the calculated output is very unstable, but it cannot be calculated from time to time, and it is difficult to control the output of light and concentrated alkali. This problem has plagued the production department for a long time and has not been effectively resolved.When the company expanded its production capacity in 2000, in order to solve this problem and achieve the purpose of accurately measuring the output of light and concentrated alkali, two new electromagnetic flowmeters were installed.However, it was soon discovered that in the measurement process, occasional inaccurate measurements would occur.The company organizes technical personnel to investigate the reasons, and draws conclusions. Many problems are not only caused by the instrument itself, but also many external working conditions are also important reasons for inaccurate measurement. Only in this way can we do
Turbine flowmeter is a commonly used flow measuring instrument, which has obvious advantages such as compact structure, intuitive and clear reading, high reliability, no interference from external power supply, anti-lightning strike, and low cost.What are the main components of the turbine flowmeter? The components of the turbine flowmeter The turbine flowmeter is a velocity flowmeter, also called an impeller flowmeter.The impeller flowmeter uses the proportional relationship between the rotational angular velocity of the impeller placed in the fluid and the fluid flow velocity, and measures the rotational speed of the impeller to reflect the volume flow of the fluid passing through the pipeline. It is one of the most accurate instruments in the flow instrument.The turbine flowmeter generally consists of the following five typical parts: 1. The material of the meter body is generally steel or cast iron, and its two ends are connected by flanges.Small-caliber gauges also use threaded connections.2. The measuring component has precision-machined blades on the turbine, which together with a set of reduction gears and bearings constitute the measuring component, and the two high-precision stainless steels supporting the turbine
Electromagnetic flowmeters will inevitably have some small errors and failures during the use process. It is not enough for us to simply perform daily maintenance and maintenance. We should still learn some frequent minor failures and some simple handling methods.Next, the editor will introduce the troubleshooting plan of the electromagnetic flowmeter in the production of acetic acid.1 There are bubbles in the medium, and there are measurement failures. The medium sucks gas from the outside or the dissolved gas in the medium turns into free bubbles. These are the two ways to generate bubble-like gas in the liquid.If there are large air bubbles in the medium, the whole electrode will be covered when the air bubbles pass through the electrode, so that the flow signal input circuit will be opened instantaneously, so the output signal will fluctuate.To determine the cause of this fluctuation, you can do this by cutting off the loop current of the magnetic field. After cutting off, if the flowmeter still displays and is still in a fluctuating state, it proves that the presence of air bubbles in the medium will cause the electromagnetic flowmeter to fluctuate.Measuring Electromagnetic Current with Pointer Multimeter
Automation instruments can be divided into six categories: on-site measuring instruments, on-site control instruments, on-site instrument actuators, display and recording instruments, adjustment control instruments, and special measuring instruments. Each category can be subdivided into several subcategories.The editor of Changhui Instrument will chat with you in detail in this article.The definition of automation instrument is that an automation instrument is composed of several automation components and is an automation technology tool with relatively comprehensive functions.Automatic instruments generally have several functions such as measurement, display, recording or measurement, control, and alarm at the same time.The origin of automation instruments The real emergence of automation instruments was in the 1980s. People effectively combined automation technology with industrial instruments through a control device, and then carried out comprehensive control through assembled electronic equipment. Later, with the control technology With the continuous development of automation technology, automation technology has gradually become the main tool for the development of industrial instruments, and real automation instruments have emerged.Microelectronics technology, computer technology, network communication
Reservoir water diversion project, the design scale is 900km3/d.The water delivery pipeline is 176km long and the diameter of the pipeline is DN2200. The real-time flow and cumulative flow data of water delivery are measured by super-large-diameter electromagnetic flowmeters.1 Principle and advantages of electromagnetic flowmeter 1.1 Principle of electromagnetic flowmeter The sensor is composed of measuring tube, excitation coil and measuring electrode and other components.The measuring principle is based on Faraday's law of electromagnetic induction.The excitation winding supplies power to generate a magnetic field. When the conductive water transmission medium passes through the magnetic field of the measuring tube, it cuts the magnetic force line and generates an induced electric potential U in the direction perpendicular to the magnetic field and flow velocity. The expression is as follows: (1) In the formula: K is the instrument structure Constant; B is the magnetic induction intensity; V is the average flow velocity; D is the inner diameter of the measuring tube.In the electromagnetic flowmeter sensor, the original voltage signal of the induced potential is a linear function of the average flow velocity, which has nothing to do with the flow velocity distribution and other characteristics of the medium.Induction potential (millimeters
What are the reasons for the inaccurate measurement of the steam vortex flowmeter: 1. Some problems in the selection of the steam vortex flowmeter: Some vortex flow sensors are selected in the caliber or in the design due to changes in process conditions. , causing it to select a size that is a little larger than usual.The actual selection should be to choose the smallest caliber as possible, so that the measurement accuracy can be improved. For example, there are several equipment used in a vortex pipeline design, because the process equipment is sometimes not used.It is that the actual flow rate is reduced, and the original design selection diameter of the actual vortex flowmeter is too large, which relatively increases the lower limit of the flow rate that can be measured.The indication cannot be guaranteed when the flow rate of the process pipeline is small. The vortex flowmeter can be used when the flow rate is large. If it needs to be rebuilt, it will be a bit difficult. flowmeter parameters to rearrange for
What are the installation requirements for the vortex flowmeter? The on-site earthquake resistance of the vortex flowmeter is not good, and the requirements for the site are very high during installation. The specific requirements are as follows: 1. Avoid strong current equipment and high-frequency equipment as much as possible , Strong switching power supply equipment.The instrument's power supply should be separated from these devices as much as possible.2. Avoid the direct influence of high temperature heat source and radiation source.If it must be installed, there must be heat insulation and ventilation measures.3. Avoid high humidity environment and strong corrosive gas environment.If it must be installed, there must be ventilation measures.4. The vortex flow meter should try to avoid installing on the pipeline with strong vibration.If it must be installed, pipe fastening devices must be added at the upstream and downstream 2D positions, and anti-vibration pads should be added to enhance the anti-vibration effect.5. It is best to install the meter indoors. When installed outdoors, pay attention to waterproofing. Special attention should be paid to bending the cable into a U shape at the electrical interface to prevent water from entering and amplifying along the cable.
How to install the input liquid level transmitter on site The input liquid level transmitter (input liquid level gauge) is characterized by flexible installation, convenient use, simple effect, on-site display signal isolation and amplification, cut-off interference design, Strong anti-interference ability Anti-condensation, anti-lightning, anti-corrosion, anti-clogging design Probe diameter 19mm ~ 42mm Optional wiring reverse and overvoltage protection, current limiting protection Ultra-wide price range, easy to choose.
The company adopts the all-intelligent electromagnetic flowmeter developed by domestic and foreign advanced technology, and its all-Chinese electromagnetic converter core uses a high-speed professional processor.The calculation speed is very fast, the accuracy is high, and the measurement performance is reliable.The sensor adopts non-uniform magnetic field technology and special magnetic circuit structure. The magnetic field is stable and reliable, and the volume is greatly reduced, which eliminates repetition and makes the flowmeter small and flowable. The measurement results are consistent with fluid pressure, temperature, density, viscosity and other physical Parameter independent, it is a true volume flow meter.Straight pipe length requirements In order to obtain normal measurement accuracy, there must be a certain length of straight pipe upstream of the electromagnetic flow sensor, but its length is comparable to most other flow meters.After 90° elbow, T-shaped pipe, concentric reducer, and fully open gate valve, it is generally considered to be a straight pipe section that is 5 times the diameter (5d) from the centerline of the electrode (not the connection surface of the sensor inlet end). Valves with different openings require 10d; the downstream straight pipe section is (2～3
A brief introduction to the pressure transmitter The pressure transmitter is an instrument that transmits the pressure value to the control room or display meter based on the pressure measurement.A sensor commonly used in industrial practice, which is widely used in various industrial automatic control environments, involving water conservancy and hydropower, railway transportation, intelligent buildings, production automatic control, aerospace, military industry, petrochemical, oil wells, electric power, ships, machine tools, pipelines, etc. industry.The following is a brief introduction to the principles and applications of some commonly used pressure transmitters. The pressure transmitter is used to measure the liquid level, density and pressure of liquid, gas or steam, and then convert the pressure signal into a 4 ~ 20mA DC signal output.Pressure transmitters mainly include capacitive pressure transmitters, diffused silicon pressure transmitters, ceramic pressure transmitters, strain gauge pressure transmitters, etc.Pressure transmitters can be divided into general pressure transmitters (0.001MPa～35MPa) and differential pressure transmitters (0～1.5MPa) according to the pressure measurement range.
The installation method of the submersible liquid level transmitter is installed in the static liquid level: when measuring the static liquid level in an open container, put the probe of the submersible liquid level transmitter directly into the bottom of the container, and use it at the opening of the container. Just fix the cable (junction box) with a nylon strap or a tripod adjustable mounting bracket.
Electromagnetic flowmeter, as a flowmeter widely used in the current process industry, often has some problems in the production of coal chemical industry. Therefore, the analysis of common problems is as follows: 1. The phenomenon of air bubbles in the liquid and the phenomenon of non-full pipes. The measurement is inaccurate or the measurement value fluctuates (output fluctuation), and the formation of bubble-like gas in the liquid has two ways: from external suction and dissolved gas (air) in the liquid into free bubbles.If the liquid contains large air bubbles, the entire electrode can be covered when the electrode is wiped, so that the input circuit of the flow signal is opened instantaneously, resulting in fluctuations in the output signal.Partial pipe phenomenon can be regarded as an extreme case of liquid containing air bubbles.The liquid is not filled with the pipe can be divided into two situations where the liquid level is higher than the level of the measuring electrode or lower than the level.When the liquid level in the pipe is higher than the electrode level, if the straight pipe section before and after the pipe system is ideal, the measurement of the electromagnetic flowmeter can be stable mostly, but the measured value of the flowmeter
At present, in the liquid level measurement industry, radar liquid level gauges have already become the preferred instrument panel for customers.There is no doubt that this is because the radar level gauge has a wider range of applications than other measuring instruments.Perhaps, all commodities have their own deficiencies.In my opinion, there are still many problems that need to be improved urgently in the radar level gauge. According to the obvious improvement of people's technological level, it is gradually improving.So, let's take a look at what levels of errors will appear in general radar level gauges? We need to listen carefully to what the technical authority* of radar level gauges say.Under normal circumstances, the error caused by the radar level gauge mainly comes from the error of the instrument panel installation, which will cause the echo signal to be interfered, resulting in measurement errors.Therefore, experts remind that at the time of installation, the aspect ratio of the tank and the size of its beam angle must be fully considered, and any large installation space should be vacated for the radar level gauge.
Turbine flowmeter is a precision flow measuring instrument with multiple signal output modes, good repeatability and high measurement accuracy. It is widely used for tap water, pure water and other gases.The main common faults of the turbine flowmeter are: 1. The shut-off valve is not closed tightly, and there is leakage: check the status of the front-end valve, the valve is closed, and no flow passes through.2. Poor shielding and grounding of the signal line: * good grounding.*Ground wire, or the metal casing of the equipment.3. There are motors, frequency converters and other high-power equipment running nearby: the turbine flowmeter should be installed away from high-power equipment and avoid strong magnetic and electric field environments.Strong magnetoelectric signals can cause spurious signals in the flowmeter.What is the reason why the signal output or flow display value is very unstable after the turbine flowmeter is installed normally?1. Unstable power supply: For turbine flowmeters that require external power supply, the quality of the power supply should be guaranteed, and the instrument power supply should be separated from the high-power equipment power supply.When necessary, through the
The instrumentation industry is a key industry in the field of automation. With the development of the global automation application environment, the number of instrumentation manufacturing companies is increasing year by year, and the demand for instrumentation is expanding steadily.Instruments and meters are widely used in the manufacturing industry. Instruments and meters are appliances or equipment used to detect, measure, observe, and calculate various physical quantities, material components, and physical parameters.In addition, instrumentation is a comprehensive product of a variety of science and technology, with a wide variety, a wide range of uses, and is constantly updated, and there are many classification methods.Specifically, it is divided according to the purpose and purpose of use, mainly including measuring instruments, automotive instruments, marine instruments, aviation instruments, navigation instruments, radio test instruments, carrier microwave test instruments, geological exploration test instruments, seismic test instruments, earth Surveying and mapping instruments, hydrological instruments, agricultural testing instruments, commercial testing instruments, teaching instruments, environmental protection instruments, etc. all belong to instruments and meters.In addition, Changhui Instrument understands that instrumentation has a wide range of applications
