CASES

In applications where hydrogen is measured, pressure transmitters or differential pressure transmitters usually use stainless steel diaphragms. However, when handling and measuring hydrogen, it is common practice to gold-plate stainless steel diaphragms. The reason behind this involves the physicochemical properties of hydrogen and its interaction with metallic materials. Here's how:   1. Characteristics and permeability of hydrogen   Hydrogen (H₂) is one of the smallest molecules in nature and is extremely permeable. Its extremely small molecular size allows it to easily penetrate many solid materials, including metals such as stainless steel. When hydrogen penetrates the stainless steel diaphragm, it can cause the following problems: Hydrogen Embrittlement: Hydrogen atoms can diffuse into the lattice of stainless steel, causing the material to become brittle. Hydrogen infiltration will cause stress concentration, resulting in brittle fracture or damage of stainless steel under mechanical stress. • Measurement error: Hydrogen permeates the back of the diaphragm, affecting the strain characteristics of the diaphragm, which in turn affects the measurement accuracy of the transmitter.       2. The necessity of gold plating   Gold plating is used to reduce or prevent the penetration of hydrogen. Gold is a high density and chemically inert metal with excellent permeability resistance. The specific reasons are as follows: Low permeability: The permeability of gold to hydrogen is much lower than that of stainless steel. This is because gold has a tighter lattice structure and a dense array of atoms, which can effectively prevent hydrogen molecules from passing through. Corrosion resistance: Gold does not react with hydrogen and is therefore able to maintain its physicochemical stability so that it does not deteriorate or corrode when exposed to hydrogen. • Reduce hydrogen embrittlement: Because gold can block the penetration of hydrogen, the stainless steel substrate is not susceptible to the diffusion of hydrogen atoms, thereby reducing or preventing hydrogen embrittlement.   3. Mechanism of gold-plating treatment   When the stainless steel membrane is gold-plated, the gold layer acts as a physical barrier, preventing hydrogen molecules from penetrating the bottom layer of the stainless steel. This treatment significantly reduces hydrogen penetration, protects the structure inside the diaphragm, maintains the mechanical strength and elastic properties of the stainless steel diaphragm, and ensures that the pressure transmitter provides stable and accurate readings when measuring hydrogen.   Technical details include:   • Thickness of the gold plating: The thickness of the gold plating needs to be thin enough not to affect the sensitivity of the diaphragm, but also thick enough to prevent hydrogen from penetrating. Usually the thickness ranges from a few microns to tens of microns. • Gold plating process: Using technologies such as electroplating or physical vapor deposition (PVD) to ensure that the gold layer is uniform and void free to enhance its permeability resistance.                         4. Application examples and practical experience   In industrial applications, hydrogen is widely used in chemical industry, energy and other fields, pressure transmitter is the key measurement equipment. If there is no gold-plated protection, the stainless steel diaphragm will gradually fail after long-term exposure to hydrogen. Therefore, when measuring the pressure in high-purity hydrogen or hydrogen-containing environments, the choice of gold-plated diaphragm can significantly improve the service life and measurement stability of the instrument.   Sum up   Stainless steel diaphragms need to be gold-plated when measuring hydrogen because of the high permeability of hydrogen and the potential hydrogen embrittlement effect on stainless steel. By gilding the membrane, an anti-permeability barrier is formed to prevent the hydrogen molecules from penetrating, ensuring the measurement accuracy and long-term stability of the device.                                                                                                                                          Thank you

When the pressure transmitter is used to measure oxygen, it needs to be deoiled and degreased, because the characteristics of oxygen make it dangerous to react with organic matter such as grease in some cases, and even cause an explosion. The reasons and scenarios for this process are explained in detail below.   Characteristics and risk analysis of oxygen 1. Strong oxidation of oxygen: • Oxygen is a strong oxidizing agent that can react quickly with some fats and organic matter. When the grease is present, the oxidation reaction may release a large amount of heat at a faster rate, resulting in local high temperatures and possibly even a fire or explosion. 2. Increased risk of pressurized environment: • When the pressure transmitter is used in a high-pressure oxygen environment, the oxidation activity of oxygen is significantly enhanced, which increases the risk of contact with grease. 3. The role of particle pollutants: In addition to oils and fats, some solid particles (such as rust or dust) may also act as catalysts for oxidation reactions, further increasing the risk.   The purpose of degreasing 1. Prevent oxidation reaction: • Degreasing removes grease or organic matter from the sensor surface or internal channels to avoid contact between oxygen and grease. 2. Improve measurement security: • The treated equipment can effectively reduce accidents caused by grease and improve the reliability and safety of system operation. 3. Ensure measurement accuracy: • Grease residue may adsorb particles or lead to blockage of internal flow channels, affecting sensor performance and measurement accuracy.   The specific method of degreasing 1. Chemical cleaning: • Clean the sensor with a special degreaser (e.g. Trichloroethylene, alcohol, etc.). 2. Ultrasonic cleaning: • Ultrasonic cleaning of sensor components to remove stubborn grease. 3. High temperature drying: • After degreasing cleaning, remove residual cleaning agent and moisture by drying. 4. Verification and inspection: • After degreasing, the treatment effect can be confirmed by UV lamp, residual oil test paper or oxygen exposure test.   When is degreasing necessary Special attention should be paid to deoiling and degreasing in the following scenarios: 1. The medium is pure oxygen or high oxygen concentration gas: • High purity oxygen (usually purity >99%) or high concentration oxygen environment, oxidation is significantly enhanced. 2. High system pressure: • When the oxygen pressure in the system is high (such as >1MPa), the reactivity of high-pressure oxygen is greatly improved, and it must be strictly degreased. 3. Medical or Aerospace applications: The safety of oxygen in medical devices (such as ventilators) and aerospace environments is extremely high and must be free of grease contamination. 4. High ambient temperature: • If the measured ambient temperature is high (e.g. >60°C), the increase in temperature will accelerate the oxidation reaction of oxygen. 5. There are highly sensitive parts: • When there are components in the system that are susceptible to contamination or reaction, such as high-precision valves or coating materials.   Under what circumstances does degreasing not need to be done? Deoiling and degreasing can not be performed under the following conditions: 1. The medium is air rather than pure oxygen: • The oxygen concentration in the general air is low (about 21%) and the pressure in most systems is low, so the risk is relatively small. 2. Low system pressure and temperature: • At low pressure (e.g., normal pressure or below 1MPa) and low temperature, the possibility of oxidation reaction is greatly reduced. 3. The system has low security requirements: • In non-critical applications, the presence of small amounts of grease in the system does not significantly affect operational safety.   Brief summary The deoiling and degreasing treatment when the pressure transmitter measures oxygen is to avoid the reaction of oil and oxygen and improve the safety of the system. The specific treatment requirements depend on the oxygen purity, pressure, temperature and application scenario. In high-purity, high-pressure oxygen systems and areas with high safety requirements, such as medical, aerospace, etc., deoiling and degreasing must be strictly carried out, while it is not necessarily required in ordinary air or conventional applications.                                                                                                                                             Thank you   

The drop type liquid level gauge is a sensor used to measure the height of liquid, especially suitable for various liquid storage tanks, rivers, reservoirs and other occasions. It determines the level height by measuring the static pressure of the liquid.   The detailed explanation of the working principle 1. Core components • Pressure sensor: detect the static pressure P=pgh generated by the liquid, and convert the pressure signal into an electrical signal. • Signal processor: Converts the electrical signal output by the sensor into a standard output signal (such as 4-20mA, 0-10V). • Ventilation cable: Balance the internal pressure of the gauge with the atmospheric pressure. 2. Pressure range design The measuring range of the submersible level gauge is determined by the pressure measuring range of the sensor, so it is necessary to select a level gauge suitable for the specific liquid depth. 3. Temperature compensation Part of the input level meter integrates a temperature sensor, which can compensate the change of liquid density caused by temperature change and improve the measurement accuracy.   The use of occasions 1. Industrial water treatment It is used in sewage treatment plants and water plants for liquid level measurement of clear pools and sumps. 2. Petrochemical industry For liquid crude oil, chemical solvent storage tank level monitoring. 3. Groundwater and environmental monitoring It can be used in groundwater level monitoring Wells, reservoir water level changes, river flood warning and other scenarios. 4. Food and beverage industry Sanitary input level gauges can be used in milk, beverage and beer storage tanks.   Advantages and Disadvantages Advantage 1. Simple structure: no moving parts, low failure rate, low maintenance cost. 2. Strong durability: Modern input level gauges can be made of stainless steel or special alloy materials, and can withstand high pressure and      a variety of chemical media. 3. High level of protection: many devices reach IP68 level and can be immersed in water for a long time. Disadvantages 1. Environmental sensitivity • Atmospheric pressure changes: Although the snorkel balances the pressure, accuracy can be affected if it is blocked or poorly sealed. • Temperature impact: Extreme temperature conditions may affect sensor stability. 2. High maintenance requirements It is easily affected by silt and impurities in dirty liquids and needs to be cleaned regularly.   Installation and maintenance precautions (detailed explanation) Installation procedure 1. Location selection Avoid stirrers or places where the flow is intense, and choose an area where the liquid flows steadily. 2. Fixing method • Use guide tubes in deep Wells or large containers to avoid sensor drift. • Use a hook, bracket, or dedicated mounting to secure the level gauge. 3. Protect the ventilation cable • Prevent ventilation cables from being broken or damaged. • Ensure that air holes are unblocked to prevent dust and water vapor from entering. 4. Cable connection • When connected to a standard signal transmitter, check the power supply polarity to prevent damage to the instrument. • Use shielded cables to avoid electromagnetic interference. Maintenance suggestion 1. Regular calibration The liquid level gauge should be calibrated regularly to prevent sensor drift from causing errors. 2. Anti-clogging measures For environments that are prone to deposition of impurities, you should consider adding a filter cover or cleaning it regularly. 3. Check the cable integrity Ensure tightness to prevent water vapor from entering and damaging internal components.   Typical application cases • Reservoir dam monitoring: The submersible level meter can be used in the reservoir's automatic water level monitoring system to provide real-time water level data for flood warning and storage management. • Industrial tank level control: For oil storage tanks in the petrochemical industry, combined with control systems to achieve level alarm and automatic control. Through the above explanation, you can have a more comprehensive understanding of the application and maintenance of the input level meter.                                                                                                                                                               Thank you                                        

       The signal output types commonly used by sensors in level switches generally have the following five types: Relay output, two-wire output, transistor output, non-contact output and NAMUR output, of which the relay output is the most widely used, transistor output and non-contact output are rarely involved, two-wire output and NAMUR output are mainly used in the intrinsic safety system, for the purpose of intrinsic safety. So what is the difference between two-wire output and NAMUR output in terms of application?       The two-wire system is a communication and power supply method relative to the four-wire system (two power supply lines, two communication lines), which combines the power supply line and the signal line into one, and the two lines achieve communication and power supply. Two-wire instruments are not connected to the power line, that is, they do not have an independent working power supply, the power supply needs to be introduced from the outside, usually for the safety gate to supply power to the sensor, the signal transmitted is passive signal. The two-wire system generally uses 4~20mA DC current to transmit the signal, and the upper limit is 20mA because of the requirements of explosion-proof: the spark energy caused by the 20mA current break is not enough to ignite the gas. The reason why the lower limit is not 0mA is to detect the broken line: it will not be lower than 4mA in normal operation, and when the transmission line is broken due to a fault, the loop current drops to 0. 2mA is usually used as the wire break alarm value, 8mA and 16mA as the level alarm value.         NAMUR standard first entered China in 2009, it was originally used in the proximity switch industry, so its working principle is defined by the proximity switch, its working principle is: The sensor needs to provide a DC voltage of about 8V, and a current signal from 1.2mA to 2.1mA will be generated according to the distance of the metal object close to the sensor. The typical value of the calibrated switching current is 1.55mA. When the current is low to high or equal to 1.75MA, an output signal will change (from 0 to 1, or from OFF to ON). When the current goes from high to low below 1.55mA, an output signal changes (from 1 to 0, or from ON to OFF). So it can check for the proximity of metal objects.          As can be seen from the working principle of the NAMUR, it is similar to the two-wire output, providing power to the sensor through the isolation gate (usually 8.2VDC, 24VDC in the two-wire system) and detecting its current signal. The NAMUR output detection point is usually ≤1.2mA and ≥2.1mA (the detection point set by different enterprises is different), the two-wire output detection point is generally 8mA and 16mA, and the switching signal is converted through the isolation grid and finally output to the DCS or PLAC control room. The difference between it and the two-wire system is that its current and voltage are smaller, and the power requirements of the safety gate used are lower, but relatively, its price is much more expensive than the output price of the two-wire system. At present, in China, the application of intrinsic safety system is more two-wire output, NAMUR output application is less, the reason is nothing more than the following two points: 1. NAMUR signal output system is expensive; 2. the intrinsic safety two-wire system output can completely replace the NAMUR output, and its price is cheaper.                                                                                                                                                    Thank you 

Process flow detection features   In order to ensure the material balance in on-line flow production, it is necessary to detect and control the flow of fluid in the pipeline. This process flow detection has some distinct characteristics, because the production is continuous, subject to the fluctuations of production required materials in a dynamic balance process, specific to a period of time stable in a flow range, and specific to a point in time every moment, can not ensure consistency. The material control of macro production is not the pursuit of absolute constancy of a point, but requires the relative stability of a range, so the error of this flow detection specific to a moment can be relaxed, but the change trend of the material should be characterized correctly. Therefore, the accuracy of this kind of process detection flow meter can be appropriately reduced, and two or even three flow monitoring meters can be selected.                                           Restrictions in the use of standard orifice plates The above defects in the use of orifice flowmeters force engineers and users to look for instruments of other structures. With the long-term accumulation of use and the efforts of instrument developers, a large number of non-standard throttling components have been developed. Although these non-standard throttling components cannot be supported by perfect experimental data as standard holes, they cannot achieve standardized production, but after long-term use and continuous improvement by manufacturers, they can meet the requirements of process flow detection. Wedge flowmeter has been widely used in many non-standard throttling components in recent years.   Wedge flowmeter structure characteristics From the appearance, the wedge flowmeter is a metal straight pipe with a connection flange welded at both ends, leaving two open interfaces in the middle of the metal pipe, and the interface has two ways of pipe mouth and flange, and the flange interface is mainly used in the industry. From the connection flange at both ends, it can be seen that there is a V-shaped protruding part that is fixed with the chamber in the body of the meter, which is the throttle element wedge block of the wedge flowmeter, and the pressure interface is opened on the front and back of the wedge block. From the appearance of the wedge flowmeter, it can be seen that the structure of the wedge flowmeter is greatly simplified, and the connector seals are reduced compared with the hole plate, and the installation and use are simpler and more convenient than the hole plate flowmeter.   Measuring principle of wedge flowmeter Wedge flowmeter is a throttling element, the structure of the throttling element is based on the Bernoulli principle - the sudden reduction of the fluid flow area caused by the static pressure dynamic pressure energy mutual conversion manufacturing, so a common throttling element is the flow area of the fluid suddenly greatly changed. The throttling element of the wedge flowmeter is a V-shaped wedge welded to the chamber of the meter body, through which the protruding wedge and the space formed by the chamber of the meter body realize the sudden change of the fluid flow area, so that the static pressure and dynamic pressure of the fluid can be converted to each other. The instantaneous flow rate of the fluid is measured by the differential pressure transmitter before and after the V-shaped wedge block, and the volume flow of the fluid flowing through the wedge flowmeter is converted.   Advantages of wedge flowmeter 1. eliminate impurities plugging It can be seen from the structure of the wedge flowmeter that the wedge is installed on one side of the surface body, and the flow area is between the wedge and the cavity in the surface body. This structure can flow through the wedge flowmeter with the fluid for impurities, particles and even larger welding slag in the medium, and will not accumulate in the surface body, so it can be used in the fluid measurement of particulate impurities that the orifice flowmeter cannot use.   2. apply to more situations The throttle wedge welded to one side of the instrument cavity produces a much smaller head (pressure) loss for the fluid passing through the body than the orifice plate with the middle opening, so the additional head loss for the hydrostatic dynamic pressure conversion process is much smaller than the orifice flowmeter. The wedge flowmeter is suitable for a wide range of fluid viscosity, which can be used for the measurement of crude oil, dirty oil, wax oil, fuel oil and even asphalt with high viscosity, and is widely used in the petroleum refining process.   3. the pressure mode change The flange pressure taking mode of wedge flowmeter simplifies the construction of throttle element + differential pressure transmitter to measure fluid flow. By using the mode of double flange transmitter, it can not only save the laying of pressure tube and tracing wire, but also significantly improve the accuracy of the measurement process of throttle element because of the stability of filling silicone oil in the capillary tube of double flange transmitter. It overcomes the additional error introduced by the qualitative change of the static medium in the pressure tube of the throttle element, reduces the failure rate and maintenance frequency of the flow meter, and improves the measuring accuracy of the wedge flowmeter as a whole.   4. energy conservation and emission reduction The head loss of wedge for overflowing fluid is less than that of orifice plate flowmeter, and the static pressure loss of wedge flowmeter and orifice plate flowmeter for the same medium should be reduced more. The detection method of wedge flowmeter + double flange transmitter eliminates the laying of pressure primer pipe, thus saving the laying of tracing heat source and the consumption of tracing steam. The pressure interface of wedge flowmeter can be insulated with the surface body and process pipeline as a whole, and the anti-freezing measures of wedge flowmeter in winter can be ensured through the heat source of the fluid itself, saving the steam energy consumption and condensate discharge of the device. The overall energy consumption of the device is reduced to a certain extent.                                                                                                                                                               Thank you    

Vortex flowmeter is a common flow measurement equipment, widely used in industrial processes to measure the flow of gas, liquid and steam. The following is a detailed explanation of its working principle, structure, operating conditions, possible problems, temperature and pressure compensation and required hardware when measuring saturated steam or superheated steam. 1. How it works Vortex flowmeters are based on the Karman vortex street principle: When a fluid flows through an asymmetric body (called a vortex generator), alternate vortices are formed downstream of it, which are generated and released at a specific frequency. The frequency of vortex generation is proportional to the flow rate of the fluid, so the flow rate of the fluid can be calculated by detecting the frequency of these vortices. Common detection methods include piezoelectric sensors or capacitive sensors to record the frequency of the vortex. 2.Structure The basic structure of vortex flowmeter includes: Vortex generators: Usually triangular columns or prisms, used to perturb the fluid and create vortices. • Sensor probes: Devices used to detect vortex frequencies, such as piezoelectric or capacitive sensors. Flow measurement pipe: A vortex generator and probe are installed in which the fluid flows through this section. • Signal processing unit: The signal collected by the probe is converted into velocity or flow data. 3. Operating conditions Vortex flowmeters are suitable for measuring the following fluids: • Gas: such as air, nitrogen, natural gas, etc. • Liquid: such as water, oil, etc. Steam: such as saturated steam and superheated steam. Note when using: • Straight pipe section requirements: To ensure accurate measurement, it is usually necessary to maintain a sufficiently long straight pipe section before and after the vortex flowmeter to avoid flow field disturbances. • Fluid velocity range: Vortex flowmeters are suitable for medium to high flow rates. • Temperature and pressure conditions: The right vortex flowmeter materials and sensors need to be selected according to the specific working conditions to adapt to higher temperature or pressure environments. 4. Common Problems Vortex flowmeter may encounter the following problems in use: Vibration effects: Pipe vibration can interfere with signal accuracy, resulting in incorrect measurement data. Low flow rate sensitivity: At low flow rates, the resulting vortex signal may not be obvious enough, reducing measurement accuracy. Scaling and corrosion: Scaling or corrosion on the inner wall of the measuring pipe can affect the performance and measurement stability of the vortex generator. • Foreign matter blocking: Foreign matter blocking the measurement pipe, will cause measurement errors 5. Temperature and pressure compensation when measuring saturated steam and superheated steam When measuring the flow of saturated or superheated steam, temperature and pressure compensation is important to ensure that the measured flow results reflect the mass flow or volume flow under actual conditions. • Saturated steam: The density of saturated steam has a fixed relationship with temperature and pressure, so the density can be calculated by measuring pressure or temperature. • Superheated steam: Since its temperature and pressure are relatively independent, the temperature and pressure must be measured simultaneously to calculate the density. Compensation method: Temperature compensation: Obtain the temperature of the fluid in real time by installing a temperature sensor. • Pressure compensation: Obtain the pressure of the fluid in real time by installing a pressure transmitter. Flow calculation: Temperature and pressure data are entered into flow calculators or automated systems for real-time density compensation to calculate accurate mass flow rates. 6. Required hardware In order to achieve accurate temperature and pressure compensation, the following hardware is usually required: • Vortex flowmeter body: equipped with standard signal output interface. Temperature sensors (such as thermocouples or thermal resistors) : used to measure the temperature of steam. • Pressure transmitter: Used to measure the pressure of steam. Flow calculators or DCS/PLC systems: used to receive temperature, pressure and flow signals and perform compensation calculations. 7. Add: Why is temperature and pressure compensation required when measuring saturated or superheated steam Temperature and pressure compensation is required when measuring saturated or superheated steam, mainly because the density of steam varies significantly with temperature and pressure. Without compensation, vortex flowmeters can only measure volume flow, and for accurate process control and energy calculation, we usually need to know the mass flow or standard volume flow. Here's why: 1. Density change of steam • Saturated steam: In the saturated state, there is a strict correspondence between the temperature and pressure of the steam. Any change in temperature or pressure results in a change in density, so density can be derived by measuring a parameter, such as temperature or pressure. However, it is still necessary to obtain the density in real time for compensation due to the change of working conditions. • Superheated steam: Temperature and pressure vary independently, and density cannot be determined simply by one parameter. Therefore, it is necessary to measure both temperature and pressure to calculate the density of the vapor. 2. Flow type and measurement target • Volume flow: The vortex flowmeter directly measures the volume flow of the fluid, that is, the volume through the measured section in unit time. For gases and vapors, this value does not directly reflect mass at different temperatures and pressures. Mass flow rate: This is a more useful quantity in process control and energy calculation as it relates to the actual mass of the fluid. When calculating the mass flow rate, you need to use the formula: • Density compensation: Through temperature and pressure measurements, real-time density is calculated and compensated to ensure that the measured result is an accurate mass flow rate or standard volume flow rate. 3. Steam energy calculation needs In many industrial applications, especially those involving steam heating or steam driven equipment, the energy transfer of steam is key. The enthalpy (heat content) of steam is directly related to its temperature and pressure. Without compensation, the data provided by the flowmeter cannot be used accurately for energy calculations. • Real-time compensation provides the true state parameters of the steam for more accurate energy balance and control. 4. Dynamic changes in actual working conditions The temperature and pressure in a steam system may change over time, such as under high or low load conditions, and this fluctuation will cause the density of the steam to change. Therefore, in order to ensure accurate measurements, these changes need to be captured and compensated dynamically. conclusion Temperature and pressure compensation is necessary for measuring saturated and superheated steam because it can: • The volume flow measured by the corrected flowmeter is mass flow. • Provides more accurate steam flow data for process control. • Ensure the accuracy of energy calculations and process efficiency. By measuring temperature and pressure in real time and combining these data for density calculations, it is possible to compensate for changes in vapor density, making measurements more reliable and accurate. conclusion Vortex flowmeter is widely used in industry because of its simple structure, easy maintenance and wide application range. When measuring saturated and superheated steam, temperature and pressure compensation is essential to ensure the accuracy and reliability of flow data.                                                                                                                                                                Thank you 

Electromagnetic flowmeter is a common industrial flow measurement equipment, and its installation requirements are strict, which is directly related to the accuracy and long-term stability of the measurement. The following is a detailed description of the installation requirements of the electromagnetic flowmeter, the reasons and the problems that may be caused by not following the installation requirements.   1. Installation requirements of electromagnetic flowmeter   1.1 Pipe location requirements   • Straight pipe length: • The upstream straight pipe section is generally required to be ≥5 times pipe diameter (D), and the downstream straight pipe section is required to be ≥3 times pipe diameter (D).              The downstream installation requirements are not met                              The downstream does not meet the installation requirements and is installed together with the regulator     • Avoid high vibration locations: • Install in areas with low vibration of pipes or equipment. • Avoid strong magnetic field interference: • Keep away from strong electromagnetic interference sources such as large motors, frequency converters, and cables. 1.2 Fluid fills the pipe   • Installation position to ensure that fluid fills the pipe: • The horizontal pipe installation of the flow meter is usually selected in the lower part of the pipe, there is a height difference at the outlet, and the vertical pipe installation flows upward to avoid gas or empty pipe phenomenon in the pipe during measurement.                              The meter transmitter is installed horizontally, the original left and right distribution of the electrode becomes the upper and lower distribution, the upper electrode is easy to be affected by bubbles, and the lower electrode may be worn by impurities in the medium. 1.3 Grounding Requirements   • Good grounding: • The ground resistance of the flow meter is usually required to be less than 10 ohms, and it should be grounded separately to avoid sharing the ground point with other equipment.   1.5 Fluid Conditions   • Avoid strong eddy or turbulent flow in the pipeline: • Ensure that the fluid is flowing uniformly at the sensor.                  Failure to meet installation requirements may cause unstable media flow                   The junction box is below, and there may be water inlet risk after long-term use 2. Reasons for installation according to these requirements   2.1 Ensure the accuracy of measurement   • The working principle of the electromagnetic flowmeter is based on Faraday's law of electromagnetic induction, which requires a fluid to flow in a magnetic field to generate an induced voltage. Therefore, a uniform distribution of fluid velocity is essential. • Insufficient straight pipe segments can cause turbulence or bias in the fluid flow, directly affecting the stability of the induced voltage and resulting in inaccurate readings.   2.2 Avoid Interference   • Strong electromagnetic fields and poor grounding can introduce interference signals, so that the sensor can not accurately perceive the weak induced voltage, affecting the stability and accuracy of the device   2.3 Ensure device service life   Bubbles, particles, and vibrations in the fluid may shock or interfere with the electrodes, affecting the life of the sensor.   3. Consequences of not following the installation requirements   3.1 Measurement error   • No straight pipe section: • Upstream or downstream fluid flow disorder, electromagnetic flow meter induced voltage fluctuations, measurement results deviate from the true value. • Fluid does not fill the pipe: • The fluid does not completely cover the electrode, and the measurement signal is distorted or even impossible to measure. • Strong vibration or bubble interference: • The output signal is unstable and the data fluctuates greatly.   3.2 Device Faults   • Poor grounding: • External electromagnetic interference into the flow meter circuit may result in false alarms or meter damage. • Improper installation position: • Long-term bubble shock or particle accumulation can wear the electrode and increase maintenance costs.   3.3 Running Interruption   • Failure of the flow meter to work properly may lead to a halt in the production process or instability in the process.   4. Conclusion   The installation requirements of the electromagnetic flowmeter are determined by its measuring principle and working characteristics. Strictly follow the installation requirements: 1. Ensure measurement accuracy; 2. Improve operation stability; 3. Extend the service life of the device.   Any behavior that does not install as required may lead to deviation of measurement data or even equipment failure, which poses risks to the production process. In order to avoid problems, the installation should carefully evaluate the site conditions and strictly follow the specifications.                                                                                                                                                     Thank you                                                                          

  Ultrasonic flowmeter is an instrument that measures liquid or gas flow through ultrasonic technology. It works on the basis that the speed at which sound waves travel through a fluid changes depending on the direction and speed of the fluid flow. Ultrasonic flowmeter is widely used in industry, petrochemical, water supply system and environmental engineering and other fields.   Working principle Ultrasonic flowmeters usually use the following two main working principles: 1. Time difference method (also known as propagation time method) : This method relies on the time difference of ultrasonic signal propagation in the fluid to measure the flow rate. Assume that there are two pairs of ultrasonic sensors, installed in the upstream and downstream positions of the pipeline, forming a symmetrical measurement path. Ultrasonic signals travel at different times in both upstream and downstream directions: a.Downstream direction: The ultrasonic signal travels in the direction of the fluid flow, and its propagation speed will be accelerated. b.Countercurrent direction: The ultrasonic signal travels against the direction of the fluid flow, and its propagation speed will be slowed down.                                                                                                                                                               DOWN            By measuring the travel time in these two directions, the flow rate of the fluid can be calculated. The difference in travel time is proportional to the velocity of the fluid. Advantages: • High accuracy: Especially suitable for single, clean liquids, the best results when the fluid does not contain impurities or bubbles. • Wide application: Suitable for measuring various pipe diameters. Cons: • Depends on the acoustic properties of the fluid: it is greatly affected by impurities or bubbles in the fluid. • Accuracy degrades in the case of fluid turbulence or uneven flow velocity distribution.   2. Doppler effect method: This method uses Doppler effect to measure flow. The Doppler effect method uses changes in the frequency of sound waves to measure velocity. Reflections occur when ultrasonic waves travel through the fluid and meet suspended particles or bubbles. If the fluid is in motion, the reflected ultrasonic frequency will be different from the emitted frequency, and this change in frequency is the Doppler effect. • When the fluid moves towards the sensor, the frequency of the reflected wave increases. • When the fluid moves away from the sensor, the frequency of the reflected wave is reduced. By measuring the difference in frequency between the transmitted and received waves, the flow rate v can be calculated.   Advantages: • Ideal for measuring fluids containing suspended particles or bubbles: not limited by fluid purity. • Wide range of application: can be used to measure dirty liquid or high bubble content of fluids. Cons: • Dependent on scattered particles or bubbles in the fluid: Sufficient reflective particles are required in the fluid to make measurements. • Low relative accuracy: The measurement results are more sensitive to noise and flow conditions.   Channel concept In ultrasonic flowmeters, channels refer to the number of paths through which ultrasonic signals propagate. Each channel consists of a pair of transmit and receive sensors that measure flow. The use of multiple channels can improve the accuracy and stability of measurement. Common channel configurations include single-channel, dual-channel, and four-channel configurations. Single channel (1 channel) : The flowmeter uses only a pair of sensors to form a measurement path. It has the advantages of low cost, simple installation, but relatively low measurement accuracy, especially in the case of uneven fluid flow distribution.    Dual channel (2-channel) : two pairs of sensors are used to form two measurement paths. The two-channel configuration significantly improves measurement accuracy because it allows the flow rate of the fluid to be sampled at different locations, reducing the impact of uneven flow distribution on measurement results.   • Four channels (4 channels) : Four pairs of sensors are used to form four measurement paths. This configuration provides higher measurement accuracy and stability for applications that require high precision measurements, such as large pipelines or environments with complex measurement conditions. The four-channel configuration can more fully reflect the flow velocity distribution of the fluid and reduce errors.                                                                                                                                                     Thank you   

  In the field of chemical engineering, there is a requirement that the length of the bolt should not be too long or too short, and the flange bolt should be left with 2 to 3 wires. For this part of the requirements, this public number has a simple introduction, see: Basic knowledge - Why should the bolt leave 2-3 wires   So how to determine the length of the bolt supporting the flange?   First of all, we definitely need to determine the thickness of the flange.   We can inquire the corresponding thickness of different types of flanges by referring to various standards. Here you can refer to GB/T 9124.1-2019 "Steel pipe flange: PN series". From this standard, we can obtain different types, different sealing surfaces, different nominal diameters and different nominal pressures under the thickness of the flange.   Secondly, we need to determine the thickness of the gasket between the flanges.   This in turn involves a series of standards, such as: GB/T 4622.1-2022 "Winding gaskets for pipe flanges Part 1: PN series" and so on. Of course, although the gasket has thickness requirements, its thickness will be reduced in the fastening state. Moreover, under normal circumstances, the thickness of the gasket is about 4 mm, so in order to quickly calculate the length of the flange supporting bolts, we can directly set the thickness of the gasket to 4 mm or 5 mm.   Then, you need to determine the length of the nut to be matched with the bolt.   This still needs to query the standard to obtain the required nut length, usually the standard to query for these two standards: GB/T 6170-2015 "Type 1 hex nut" GB/T 6175-2016 "Type 2 hex nut".   We can see that the nut length of a type 1 nut is about 0.8 times its large diameter. The length of a type 2 nut is approximately 1 times its large diameter. Therefore, we can quickly determine the length of the nut by the screw thread type of the nut, usually we choose 1 times the size of the nut.   In addition, we also need to determine the length of the reserved bolt.   Since our bolt needs to leave 2 to 3 wires after fastening the nut, it is necessary to determine the corresponding length of these 2 to 3 wires. We also need to query the corresponding standards, such as: GB/T 196-2003 "Basic dimensions of ordinary threads". From the standard, we can obtain the corresponding pitch of different types of threads, so as to calculate the length required for 2 to 3 threads.   Finally, we also need to determine the number of bolts and thread specifications corresponding to a flange. These two data can also be obtained from the standard GB/T 9124.1-2019 "Steel pipe Flanges: PN Series". The standard lists different flange types, nominal pressures, the number of bolts corresponding to nominal diameters, and bolt thread specifications. After the above steps, we can calculate the length of the bolt required, the length of the bolt includes: the thickness of two threads, the thickness of the sealing gasket, the thickness of the two nuts, and the height of the reserved 4~6 threads. The above calculation process is very complex and requires querying a large number of criteria. Moreover, the calculation process is complicated and time-consuming.   How to solve it? Coincidentally, in order to solve the query and calculation problems of flange matching bolts, this public update adds the query and calculation function of the number and length of flange matching bolts.   The new function is located in the flange model screen. By selecting the flange type, you can quickly query the number and length of bolts supported by the flange.                                                                                                                                                 Thank you   

Coriolis mass flowmeter is based on the Coriolis principle, so that the medium flows through the flow tube vibration, the sensor detects and analyzes the flow tube frequency, phase difference and amplitude changes, directly measure the current flow of the flow tube media quality, from the vibration frequency, calculate the density. Multiple process variables of the pipeline can be measured at the same time, such as: mass flow, volume flow, density, temperature.         Coriolis Flow meter VS Thermal Flow meter: Coriolis flowmeters measure mass flow directly. Direct mass flow measurement reduces inaccuracies caused by fluid physical properties. Thermal flowmeters measure mass flow indirectly. There are fundamental differences between the two devices because of the way they are measured, and therefore the applications for which they are suitable are also different. Thermal mass flowmeters use the heat capacity of a fluid to measure mass flow. The device is equipped with a heater and 1 or 2 temperature sensors for heating (1 sensor) the applied power or temperature difference between the 2 sensors is directly proportional to the fluid mass flow rate. Thermal mass flowmeters are mainly used for gases. Because the Corrioli principle directly measures the mass flow rate, Corrioli flowmeters can be used for gases and liquids.   Applications: Coriolis mass flowmeters can be used to measure the mass flow of changing or unknown gas or liquid mixtures or to measure supercritical gases. It not only directly measures the mass flow rate, but also has high accuracy and good repeatability. Coriolis flow meters are flexible, reliable and accurate flow meters.                                                                                                                                               Thank you 

✦Principle The metal tube float flowmeter has the advantages of simple structure, reliable operation, high accuracy and wide application range. It can withstand higher pressures than glass rotameters. NYLZ-L series flowmeters have local indication, electrical remote transmission, limit switch alarm, corrosion resistance, jacket type, damping type and explosion-proof varieties. Widely used in national defense, chemical, petroleum, metallurgy, electric power, environmental protection, medicine and light industry and other departments of liquid, gas flow measurement and automatic control. When the bottom-up fluid passes through the upright measuring tube, the float rises under the action of the pressure difference, and the height of the float rise represents the size of the flow. The magnetic steel in the float is coupled with the magnetic steel in the indicator and transferred to the indicator to drive the pointer in the indicator to rotate.                             ✦Show fault phenomenon Valve fully closed, flowmeter indicates full scale   ✦Process check 1, the valve is fully closed, the flow meter indicates full scale, first consider the flow meter rotor stuck. 2, whether the rotameter head is damaged, whether the cone tube is blocked.     ✦Treatment method 1. Use a screwdriver to absorb the magnetic part of the rotameter to initially check the reaction of the flowmeter, normal, no falling off phenomenon, tap the bottom of the flowmeter with a rubber hammer, and still show the full scale, and judge it as the rotameter card. 2. Remove the thermal insulation cotton, open the heat tracing, wear gloves, and prepare to remove the flow meter. 3, remove the four screws of the lower flange, the force should be uniform, and then remove the screws after the pressure is discharged. 4, remove the flow meter, remove the circlip, remove the rotor, the rotor is attached with iron powder. Wipe off with a rag and rinse with water. 5. Install the rotor, move up and down with the screwdriver against the rotor, move flexibly, and install the flowmeter. 6, the flow meter to the process use, normal operation.                                                                                                                                             Thank you 

Pressure transmitters are one of the most common sensor types used in industrial automation control. Piezoresistive type, capacitive type and monocrystalline silicon resonant type are three main types, each with its own unique working principle, advantages and disadvantages and application scenarios   Piezoresistive pressure transmitter Working principle Piezoresistive pressure transmitters use the piezoresistive effect of monocrystalline or polysilicon to convert mechanical deformation caused by pressure into electrical signals: 1. The pressure acts on the sensing diaphragm, and the diaphragm becomes elastic deformation. 2. The piezoresistive element (resistor) on the diaphragm changes its resistance value due to force. 3. The resistance change is converted into a voltage signal through the Wheatstone bridge, and the output electrical signal is proportional to         the pressure.   Advantages: 1. High precision. 2. Simple structure and low cost. 3. Fast response speed, suitable for dynamic pressure measurement.   Disadvantages: 1. It is sensitive to temperature and needs temperature compensation. 2. Susceptible to mechanical vibration. 3. General long-term stability, large drift.   Application scenario • Pressure measurement of liquids, gases and vapors. • Extensive engineering applications, such as water treatment equipment, automotive oil pressure, refrigeration systems, etc.   Capacitive pressure transmitter Working principle Capacitive pressure transmitter uses pressure to cause capacitance change principle: 1. The pressure acts on the metal or non-metal diaphragm, causing elastic deformation of the diaphragm. 2. The diaphragm and the fixed electrode form a variable capacitor, and the pressure change causes the capacitance value to change. 3. The capacitance change is converted into an electrical signal, and the output signal is proportional to the pressure.    Advantages: 1. High sensitivity, especially suitable for small pressure measurement. 2. Low temperature effect, good long-term stability. 3. Suitable for high and low pressure measurement.   Disadvantages: 1. Sensitive to impurities, moisture and other environments, requiring special treatment. 2. The signal processing is complex and the cost is relatively high. 3. The response speed is slightly slower than piezoresistive type.   Application scenario • Precision scenarios, such as medical air pressure, food processing equipment. • High temperature, high pressure, highly corrosive conditions, such as chemical and petroleum industries.   Monocrystalline silicon resonant pressure transmitter Working principle Monocrystalline silicon resonant pressure transmitter uses the principle of resonant frequency change in monocrystalline silicon: 1. Micro resonators are processed on the monocrystalline silicon diaphragm. 2. The pressure causes the deformation of the diaphragm, resulting in the stress change of the resonator. 3. Stress change changes the vibrational frequency of the resonator. 4. After measuring the resonant frequency change, calculate the pressure value through the algorithm.   Advantages: 1. High precision 2. Good long-term stability, small drift, suitable for long-term measurement. 3. Strong anti-interference ability, insensitive to electromagnetic and environmental interference. 4. Suitable for high temperature, high pressure and harsh environment.   Disadvantages: 1. High manufacturing cost and high price. 2. The response speed is slightly slow, suitable for static or quasi-dynamic measurement. 3. Complex design and calibration.   Application scenario Applications that require high accuracy and reliability, such as oil and gas pipelines, aerospace pressure measurement. • Metrology and research equipment.