What is meant by Modbus protocol?

Modbus Protocol is a serial communication protocol, which was published by Modicon company (now Schneider Electric) in 1979 for the use of programmable logic controller (PLC) communication. Modbus has become the industry standard (De facto) of communication protocols in the industrial field and is now a common connection method between industrial electronic devices.

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Modbus Protocol Features

The main reasons why Modbus is more widely used than other communication protocols are:

• Published publicly and without copyright requirements
• Easy to deploy and maintain
• For suppliers, there are not many restrictions on modifying mobile local bits or bytes

Modbus allows multiple (approximately 240) devices to be connected on the same network to communicate. For example, a device that measures temperature and humidity and sends the results to a computer. In the data acquisition and monitoring control system (SCADA), Modbus is usually used to connect the monitoring computer and the remote terminal control system (RTU).

How does a Modbus work?

Modbus is a master/slave communication mode with a single master station. There can only be one master station on the Modbus network, and the master station has no address on the Modbus network. The address range of the slave station is 0-247, where 0 is the broadcast address. The actual address range of the slave station is 1-247. Modbus communication standard protocol can be transmitted through various transmission methods, such as RS232C, RS485, optical fiber, radio, etc.

Modbus has two serial transmission modes, ASCII and RTU. They define different ways of how data is packaged and decoded. Devices that support Modbus protocol generally support the RTU format. Both communication parties must support one of the above modes at the same time.

The above is the official definition, let’s use ordinary words to explain:

This is actually the communication protocol, and any protocol is similar. There are only two communication formats and communication specifications.

If you want, you can also define a communication specification yourself. Use PLC or VB language to process according to this specification defined by yourself. If the reliability exceeds Modbus, then your communication specification is the most popular!

The difference and connection between RS 485 and MODBUS

I often see RS485 and MODBUS written together, and Sino-Inst will talk to you about the difference and connection between RS485 and MODBUS.

RS485 is a physical interface, which is simply hardware.

MODBUS is an international standard communication protocol used to exchange data between devices of different manufacturers (usually for industrial purposes); the so-called protocol can also be understood as the “language” someone said above, or simply software.

Under normal circumstances, two devices transmit data through the MODBUS protocol: RS232C was first used as the hardware interface, (that is, the serial communication port (serial port) on an ordinary computer). There is also RS422, and there is also commonly used RS485. This interface The transmission distance is long, and it is often used in general industrial scenes.

The MODBUS protocol is divided into three modes: MODBUS RTU, MODBUS ASCII and the later developed MODBUS TCP.

The physical hardware interfaces used by the first two (MODBUS RTU, MODBUS ASCII) are serial (Serial) communication ports (RS232, RS422, RS485).

And MODBUS TCP is to conform to the development trend of the world today. Anything can be connected by Ethernet or Internet to transmit data.

The hardware interface of MODBUS TCP mode is the Ethernet (Ethernet) port, which is the network port generally used on our computer.

We categorize industrial networks into three categories: RS485 network, HART network and fieldbus network.

HART network

HART is a transitional bus standard proposed by Emerson. It mainly superimposes a digital signal on top of a 4-20 mA current signal.

The physical layer uses BELL202 frequency shift keying technology. In order to realize the functions of some smart meters. But this agreement is not a truly open standard, and you have to join his foundation to get the agreement. Part of the cost of joining the foundation.

The technology is mainly monopolized by several large foreign companies, and in the past two years, some domestic companies have started to do it again. But it has not yet reached the level of foreign companies.

Nowadays, a large part of smart meters are equipped with HART round cards and all have HART communication function.

But from the domestic point of view, this part of the function has not been really used, at most it is only used to set the parameters of the handheld communicator. The HART intelligent instrument has not played its due function, and it has not been connected to the Internet for equipment monitoring.

In the long run, due to the low communication rate of HART, the networking is difficult and other reasons. The procurement volume of HART instruments will experience a downward trend.

However, because HART instruments have a history of more than ten years, the number of instruments installed is very large. For some system integrators, there is still a lot of room for use.

Fieldbus network

Fieldbus technology is one of the hotspots of technology development in the field of automation today. Known as the computer local area network in the field of automation. Its appearance marks the beginning of a new era of automation control technology.

Fieldbus is a digital, serial, multi-station communication network that connects the instruments installed in the control site and the control equipment installed in the control room. The key symbol is the ability to support bidirectional, multi-node, bus-style all-digital communication.

In recent years, fieldbus technology has become a hot spot in the development of automation and instrumentation in the world. The appearance of the fieldbus network is a revolutionary change in the traditional control system structure. It is the automatic control system that is moving in the direction of intelligence, digitization, informationization, networking, and decentralization. Form a new type of network integrated fully distributed control system-Fieldbus Control System FCS (Fieldbus Control System).

However, various standards of current fieldbus exist in parallel and have their own areas of survival. There has not yet been a truly unified standard. The key is that we cannot see when a unified standard will be formed, and the technology is not mature enough.

In addition, the types of fieldbus instruments are still relatively small, and the room for selection is small, and the price is relatively high. From the perspective of end users, most of them are still on the sidelines. I want to wait until the technology is mature and consider it, but now there are few implementations.

RS485 network

RS485/MODBUS is a popular way of network layout. Its characteristic is simple and convenient to implement. And now there are many instruments that support RS485, especially in the oil industry.

RS485/MODBUS is simply dominating the world. Current instrument vendors have also switched to support RS485/MODBUS. The reason is simple, like the original HART instrument, it is very difficult and expensive to buy a conversion port. The RS485 conversion interface is much cheaper and has a wide variety.

At least in the low-end market, RS485/MODBUS will still be the most important networking method, and it will not change in the past two to three years.

Features of 4-20mA current loop and RS485 communication (Modbus RTU protocol) data acquisition

4-20mA current loop data acquisition characteristics

Use pressure, temperature transmitter and current acquisition module (RTU) or acquisition card on site for data acquisition and then communicate and transmit with the industrial computer. The data acquisition system using 4-20mA current loop instrument has the following characteristics:

1. The construction is complicated, data cables need to be buried in advance, the number of cables is large, and the construction period is long
2. The computer terminal needs a current acquisition card or a data acquisition module
3. Complicated replacement and maintenance operations, troublesome expansion
4. 4-20mA current loop data acquisition accuracy is low, and the error comes from 4-20mA output instrument and acquisition card (or data acquisition module)

RS485 communication (Modbus protocol) data acquisition characteristics

Use smart meters, transmitters, actuators, etc. with RS485 communication to directly communicate with the serial port of the industrial computer. The use of RS485 communication digital sensor meter network system has the following characteristics:

1. The construction complexity is reduced, data cables need to be buried in advance, the number of cables is small, and the construction period is reduced
2. The computer terminal only needs an isolated RS485/RS232 converter
3. Easy to replace and maintain, and easy to expand
4. High acquisition accuracy, eliminating the error of RTU, the system error only comes from the transmitter itself
5. RS485 communication has good transmission stability and less network maintenance
6. The cost of use is greatly reduced|
7. The maximum communication distance of RS485 is 1200 meters

RS485 communication transmission of electromagnetic flowmeter Modbus protocol

The RS485 communication data transmission interface of the electromagnetic flowmeter is half-duplex. The standard rate is greater than 250kHz. The communication direction conversion time is 3.5us. Usually 16-way load can be connected. It can also be expanded to 32 channels. Standard shielded twisted pair cable is 1000m. Use master-slave multi-machine communication. When multiple electromagnetic flowmeters are interconnected. It can save signal lines and facilitate high-speed transmission.

RS-485 communication has good anti-noise interference. Long transmission distance and multi-station capability. Will not affect the synchronization of on-site and remote data due to PLC failure.

However, the electromagnetic flowmeter must have a 485 interface and support the MODBUS RTU protocol.

In order to maintain stability, it is better to use electromagnetic flowmeters of the same manufacturer and the same brand when communicating with multiple flowmeters.

RS485 is a kind of industrial data bus. The electromagnetic flowmeter has RS485 serial communication so that digital communication replaces the transmission of PLC analog signals and ordinary switch signals. The PLC simulation calculation is reduced, and the accurate data collection and transmission are realized.

RS485 precession vortex flowmeter

Precession vortex flowmeter is a new type of gas flowmeter. It can be used for the measurement of natural gas, propane, air, nitrogen and other gases.

The converter can output frequency pulse, 4 ~ 20mA analog signal, and has RS485 interface, can be directly connected to the computer network, transmission distance up to 1.2km;

Precession Vortex Gas Flowmeter, like vortex flowmeter, is a velocity flowmeter. The cost performance of the intelligent precession vortex flowmeter is higher than vortex flowmeter. The intelligent precession vortex flowmeter can only measure gas. Precession Vortex Gas Flowmeter can be made into an integrated temperature and pressure compensation. And can measure various gases. Such as compressed air, oxygen, biogas, natural gas, coal gas, etc.

Read more about Everything You Need To Know About Electronic Flow Meters

KimGuo11

Wu Peng, born in 1980, is a highly respected and accomplished male engineer with extensive experience in the field of automation. With over 20 years of industry experience, Wu has made significant contributions to both academia and engineering projects.

Throughout his career, Wu Peng has participated in numerous national and international engineering projects. Some of his most notable projects include the development of an intelligent control system for oil refineries, the design of a cutting-edge distributed control system for petrochemical plants, and the optimization of control algorithms for natural gas pipelines.

drurylandetheatre.com

Magnetic flowmeters are mainly used to measure the flow of conductive media with good fluidity. Magnetic flowmeters are divided into insertion type and pipeline type. Pipeline electromagnetic flowmeter and insertion electromagnetic flowmeter has the same requirements for installation. There are also different places. Generally speaking, there are requirements for the external environment and installation methods.

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What is magnetic flow meter and its uses?

A magnetic Flow Meter is a flow meter that measures the flow of conductive fluids. Abbreviated as EMF, also called Electromagnetic flowmeters. It is a kind of Volumetric flow meter. A magnetic flow meter measures the velocity of conductive liquids moving through a pipe or conduit. In the wastewater treatment industry, a Magnetic Flow Meter is the best flow meter choice.

Electromagnetic flowmeters have been used for more than 50 years and have been widely used worldwide. The fields involve water/sewage, chemical, pharmaceutical, paper, food, and other industries.

• Water / Wastewater Industry
• Food and Beverage
• Metals
• Brewing, Distilling, and Wine makening
• HVAC
• Chemical
• Pulp and Paper
• Pharmaceutical
• Mining, Mineral Processing

Extended reading: How to Select the Right Agriculture Flow Meter

How does a magnetic flowmeter work?

Magnetic flowmeters use the principle of Faraday’s Law of Electromagnetic Induction to measure the flow rate of liquid in a pipe. In the magnetic flowmeter pipe parts, a magnetic field is generated and channeled into the liquid flowing through the pipe. 

Faraday’s Law states that the voltage generated is proportional to the movement of the flowing liquid. A conductor moving through a magnetic field produces an electric signal within the conductor. And the singal is proportional to the velocity of the water moving through the field. 

As fluid flows through the magnetic field, conductive particles in the fluid create changes. This variation is used to measure and calculate the velocity of water flow through the pipe. When the fluid moves faster, more voltage is generated. The electronic transmitter processes the voltage signal to determine the liquid flow.

To learn more about Magnetic Flow Meters, this video by Emerson gives a good explanation.
Video source: https://www.youtube.com/watch?reload=9&v=lRSjYjg9WRo

Read more about Everything You Need To Know About Electronic Flow Meters

magnetic flow meter conductivity requirement

The premise of using an electromagnetic flowmeter is that the liquid to be measured must be conductive and cannot be lower than the threshold (ie, the lower limit). If the conductivity is lower than the threshold value, measurement errors will occur until it cannot be used. The threshold value of general-purpose electromagnetic flowmeters is between 10-4~(5×10-6)S/cm, depending on the model. The general conductivity threshold is 5×10-6S/cm=5μS/cm. the

The conductivity of industrial water and its aqueous solution is greater than 10-4S/cm. The conductivity of acid, alkali and salt solution is between 10-4 and 10-1S/cm. There is no problem in use, and the low-grade distilled water is 10-5S/cm cm is also not a problem.

Petroleum products and organic solvents cannot be used if their conductivity is too low.

Some pure liquids or aqueous solutions have low conductivity and are considered unusable. However, in the actual work of electromagnetic flowmeters, there will be instances where they can be used because they contain impurities, which are beneficial to increase the conductivity.

For the aqueous solution, the conductivity in the data is measured in the laboratory with pure water. The actual aqueous solution may be mixed with industrial water. The conductivity will be higher than that found. It is also conducive to flow measurement.

Step 1: Magnetic Flowmeter Installation environment requirements

In order to make the electromagnetic flowmeter work stable and reliable, the following requirements should be paid attention to when choosing the installation location:

1. Try to avoid ferromagnetic objects and equipment with strong electromagnetic fields (large motors, large transformers, etc.). In order to prevent the magnetic field from affecting the working magnetic field and flow signal of the sensor.
2. Install in a dry and ventilated place as much as possible. Avoid sun and rain. The ambient temperature should be -20 ～ +60 ℃. The relative humidity is less than 85%.
3. There should be ample space around the flowmeter. Easy to install and maintain.

Extended reading: Ultrasonic Insertion Flow Meter for Lined/Large Pipes

Step 2: Magnetic Flowmeter Installation Location selection

The electromagnetic flowmeter can be installed on a horizontal pipe or a vertical pipe.

1. Choose a straight pipe section filled with liquid, such as the vertical section of the pipeline (flow direction from bottom to top is appropriate) or a liquid-filled horizontal pipe (the lowest point in the entire pipeline is appropriate). The position must ensure that the pipeline is always filled with the measured fluid . In the process of installation and measurement, there must be no partial full pipe.
2. Select the place where the fluid flow pulse is small. That is, it should be far away from pumps, valves, elbows and other local resistance parts.
3. When measuring two-phase (solid, liquid or gas, liquid) fluids, choose a place that is not easy to cause phase separation.
4. Avoid negative pressure at the measurement site.
5. The diameter or circumference of the side pipe is easy to measure, and the ovality should be small.
6. Straight pipe length: The length of the straight pipe on the upstream side of the sensor installation pipeline should be greater than or equal to 10D, and the downstream side should be no less than 5D.
7. There are two methods for inserting the insertion point of the plug-in electromagnetic flow sensor: one is to insert it on the central axis of the pipe under test, and the other is to insert it at 0.25D where the inner wall of the pipe is the pipe.
8. Vertical installation: when the sensor is inserted into the pipe, the angle between the vertical diameter of the pipe section and the pipe section should be less than 5°, which is suitable for measuring clean media with small pipe vibration.
9. Tilt installation: the angle between the axis of the sensor and the axis of the pipeline being measured is 45°. It is suitable for liquid flow measurement with large pipe diameter and other impurities in the measuring medium. This installation method has low water resistance and is not suitable for entanglement.

Step 3: Mounting flange for Magnetic Flowmeter Installation

A. Select the installation location and select the front and rear straight pipe sections of appropriate length. Cut the pipe section where the flowmeter is installed;
B. Weld a flange on each of the front and rear straight pipe sections. After adding gaskets at both ends of the sensor, connect the sensor to the flange with stud bolts (note that the direction of the arrow on the meter body should be consistent with the direction of fluid flow);
C. Weld the front and rear straight pipe sections of the sensor to the original pipe.

Note:

1. When welding, ensure that the flange end face is perpendicular to the centerline of the pipeline;
2. The place where the mounting hole pitch is larger is the meter rod mounting position. And the direction of the mounting holes of the two flanges should be the same;
3. After the flange is welded, the pipeline should be cleaned up and there should be no welding slag and other sundries.

Extended reading: Magnetic Large Dia. Pipe Flow Meter

Step 4: Converter installation and connection cables

Power and signal wiring. Please refer to the product manual accompanying the goods.

The converter of the split electromagnetic flowmeter should be installed near the sensor where it is convenient for reading and maintenance. It can also be installed in the instrument room, and its environmental conditions can be much better than the sensor.

The distance between the converter and the sensor is limited by the conductivity of the measured medium and the signal of the signal cable. That is, the distributed capacitance of the cable, the cross-section of the wire, and the number of shielding layers. Use the information cable provided with the instrument by the manufacturer.

For liquids with lower conductivity and longer transmission distances, three-layer shielded cables are also specified.

The general instrument “Instruction Manual” gives the corresponding transmission distance range for liquids with different conductivity.

When a single-layer shielded cable is used for industrial water or acid-base liquids, the transmission distance is usually 100m.

In order to avoid signal interference, the signal cable must be worn separately in a well-grounded steel protection tube. Never put the signal cable and the power cord in the same steel pipe.

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Special Magnetic Flowmeter Installation situation

For pipelines that do not allow flow interruption in the process, a bypass pipe should be installed and cleaned when the flow meter is installed. As shown in the figure, this device ensures continuous operation of the equipment system when the flow meter is withdrawn from use.

The inner diameter measured by the flowmeter should be consistent with the inner diameter of the pipe. If the inner diameter cannot be the same, the inner diameter of the pipe should be greater than the inner diameter of the flowmeter. And install a tapered tube or expansion tube with a cone angle not greater than 15 between them, as shown in the figure.

When the flowmeter is installed inclined or vertically, the flow direction should be from top to bottom, as shown in the figure.

All Magnetic Flowmeter Installations. It cannot be described in detail here. If you encounter problems with the Magnetic Flowmeter Installation. Please contact our engineers in time. We will guide the Magnetic Flowmeter Installation for you.

Featured Magnetic Flowmeters for Sale

More Flow Measurement Solutions

Sino-Inst offer over 50 Magnetic Flow Meters, with Best Price.

A wide variety of Magnetic Flow Meters options are available to you, such as free samples, paid samples.

About 13% of these are magnetic flow meter, 14% are Insertion Magnetic Flow Meter, 25% are Venturi flow meter, 13% are ultrasonic flow meter, and others are Liquid Turbine Flow Meters.

Electromagnetic flowmeters can be divided into insertion electromagnetic flowmeters and pipeline electromagnetic flowmeters. The Magnetic Flowmeter Installation methods of insertion electromagnetic flowmeters and pipeline electromagnetic flowmeters have the same place, but there are also differences.

First of all, what we need is that the shielded wire of the electromagnetic flowmeter cannot be routed together with the cable, because this will cause interference. Under normal circumstances, the parameters of the inner head of the electromagnetic flowmeter are set in advance, so no other adjustments are required.

Magnetic Flowmeter Installation should avoid places where the temperature rises and falls too much, and places where there are magnetic fields and strong vibration sources.

Sino-Inst is Magnetic Flow Meters supplier, located in China. Magnetic Flow Meters products are most popular in North America, Mid East, and Eastern Europe. The United States, and India, which export 99%, 1%, and 1% of Magnetic Flow Meters respectively.

For how to install the electromagnetic flowmeter, the details of Magnetic Flowmeter Installation, if you have any questions and ideas, please feel free to contact us.

KimGuo11

Wu Peng, born in 1980, is a highly respected and accomplished male engineer with extensive experience in the field of automation. With over 20 years of industry experience, Wu has made significant contributions to both academia and engineering projects.

Throughout his career, Wu Peng has participated in numerous national and international engineering projects. Some of his most notable projects include the development of an intelligent control system for oil refineries, the design of a cutting-edge distributed control system for petrochemical plants, and the optimization of control algorithms for natural gas pipelines.

drurylandetheatre.com

The solvent flow meter is a flow meter that can measure solvent volume or mass flow. In the industrial production process, it is very important to accurately measure the amount of solvent. Solvents are divided into organic solvents and inorganic solvents according to their chemical composition. Solvents are commonly used raw materials in various industries such as coatings, paints, and dyes.

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More Flowmeters

Solvent flow meter – Oval Gear

An Oval Gear flowmeter as a mechanical flow meter is a common type of Volumetric Flow Meter. It can measure the volume flow of high viscosity and corrosive Solvent fluids.

• High measurement accuracy;
• The installation pipeline conditions have no influence on the measurement accuracy;
• Can be used for high-viscosity liquids;
• Wide range;
• The direct-reading meter can directly obtain the cumulative and total amount without external energy.
• Clear and clear, easy to operate.

Extended reading: Mechanical flow meter types

Solvent flow meter – Turbine

Turbine flow meters are velocity flow meters, also called impeller flow meters. Can be used to measure the instantaneous flow and cumulative flow of Solvent liquids.

Turbine flowmeters are widely used in flow measurement: petroleum, organic liquids, inorganic liquids, liquefied gas, natural gas, coal gas and cryogenic fluids. Turbine flowmeter signals can be divided into pulse signals or current signals (4-20mA). It is suitable for use with secondary display, PLC, DCS and other computer control systems.

Turbine Flow Meter reference price: USD 200-1700/pc.

Extended reading: non contact flow meter

Solvent flow meter – Electromagnetic

Magnetic Flow Meter is a flow meter that measures the flow of conductive Solvent fluids. Abbreviated as EMF, also called Electromagnetic flowmeters. It is a kind of Volumetric flow meter. A magnetic flow meter measures the velocity of conductive liquids moving through a pipe or conduit. In the wastewater treatment industry, Magnetic Flow Meter is the best flow meter choice.

• Measures liquids or liquid slurries that have a minimum conductivity of 5 µS/cm.
• Sanitary type, PTFE anticorrosive materials are optional.
• Clamps, flanges, insertion installation are optional.
• Battery powered optional.
• Low cost.
• DN 6 to DN2000
• High precision: 0.5%, 0.2% optional

Extended reading: How to Select the Right Agriculture Flow Meter

Solvent flow meter – Gear

Gear flow meter is a micro digital positive displacement flow meter. Can measure very small flow rates and quantify small volumes of liquid. High and low-temperature resistance (-196℃-200℃).

The Gear flow meter for Microflow is made of stainless steel and is used for precise continuous or intermittent measurement of the flow or instantaneous flow of liquid. It is especially suitable for the flow measurement of heavy oil, polyvinyl alcohol, grease, and other high-viscosity media. It can measure the viscosity of Fluid up to 10000Pa.s.

Generally speaking, we can choose a suitable flow meter according to the different characteristics of chemical solvents. For example, high-viscosity solvents are recommended to use gear flow meters. For example, for corrosive solvents, electromagnetic flowmeters can be used. If you need to reduce costs, you can choose a turbine flowmeter.

Of course, it needs to be based on our actual measurement conditions, such as the temperature of the medium, the temperature of the pipeline, the pressure, and so on. Select the appropriate flow meter to achieve accurate measurement.

Extended reading: Cylinder Gear flow meter for micro flow measurement.

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Extended Reading: Special Magnetic Flowmeter Installation situation

Sino-Inst, Manufacuturer for Solvent flow meters.

Sino-Inst’s Solvent flow meters, made in China, Having good Quality, With better price. Our flow measurement instruments are widely used in China, India, Pakistan, US, and other countries.

KimGuo11

Wu Peng, born in 1980, is a highly respected and accomplished male engineer with extensive experience in the field of automation. With over 20 years of industry experience, Wu has made significant contributions to both academia and engineering projects.

Throughout his career, Wu Peng has participated in numerous national and international engineering projects. Some of his most notable projects include the development of an intelligent control system for oil refineries, the design of a cutting-edge distributed control system for petrochemical plants, and the optimization of control algorithms for natural gas pipelines.

drurylandetheatre.com

What is a Grease Flow Meter?

Grease Flow meters are meters dedicated to measuring the volume or mass flow of industrial grease fluids.

The most common Grease Flow meters are elliptical gear flow meters, also called positive displacement flowmeters. There are turbine flow meters, gear flow meters, and so on. Industrial grease can be measured online. Including hydraulic oil, steam turbine oil, refrigeration oil, heat treatment oil and heat transfer oil, etc. In addition, there are greases with lubricating oil as base oil and thickening agent.

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More FlowMeters

Industrial Grease Flow meters are different from grease guns or grease meters. Industrial Grease Flow meters need to deal with more complex conditions. The pipe diameter can range from DN10 to DN200, or even larger. So how to choose the applicable Industrial Grease Flow meters? Let’s analyze it together.

Characteristics of industrial grease

What are the types of industrial grease?

Industrial greases mainly include hydraulic oil, gear oil, turbine oil, compressor oil, refrigeration oil, transformer oil, vacuum pump oil, bearing oil, metal processing oil (liquid), anti-rust grease, cylinder oil, heat treatment oil, and heat transfer oil.

Extended reading: High Temperature Flow Meter

In addition, there are greases with lubricating oil as base oil and thickening agent. The users of industrial lubricants are companies from all walks of life, and they use many varieties and large amounts.

The basic performance and main selection principle of industrial grease is viscosity. GB/T3141-94 is the ISO viscosity classification of industrial liquid lubricants, which is equivalent to the international standard ISO3448-1992 “Industrial Liquid Lubricants-ISO Viscosity Classification”.

So, when we choose an industrial grease flow meter, we first need to consider the viscosity of the grease. Then consider the flow range and temperature. And other special requirements of users.

Our commonly used industrial grease flow meters are oval gear flow meters, turbine flow meters, and gear flow meters. There is also a mass flow meter. Next, let’s discuss separately.

• Oval Gear
• Turbine
• Gear
• Mass

Grease Flow Meters-Oval Gear

Oval gear flowmeter is a volumetric meter for continuous or intermittent measurement and control of liquid flow in a pipeline.

Oval gear flowmeter, also known as positive displacement flowmeter. A positive displacement flowmeter as a mechanical flow meter is a common type of Volumetric Flow Meter. It can measure the volume flow of high viscosity and corrosive fluids.

• Volumetric Flow Meters
• High measurement accuracy;
• The installation pipeline conditions have no influence on the measurement accuracy;
• Can be used for high-viscosity liquids;
• Wide range;
• The direct-reading meter can directly obtain the cumulative and total amount without external energy.
• Clear and clear, easy to operate.

Therefore, we recommend that when the grease viscosity is high, you can first consider using an oval gear flowmeter.
Viscosity: 0.6—2mPa.s—200mPa.s—1000mPa.s-2000mPa.s.
Temperature: -20~+200℃

Extended reading: Sanitary Positive Displacement Flow Meter

Grease Flow Meters-Turbine

Turbine flow meters are velocity flow meters, also called impeller flow meters. Can be used to measure the instantaneous flow and cumulative flow of liquids and gases.

Turbine flowmeters are widely used in flow measurement: petroleum, organic liquids, inorganic liquids, liquefied gas, natural gas, coal gas, and cryogenic fluids. Turbine flowmeter signals can be divided into pulse signals or current signals (4-20mA). It is suitable for use with secondary display, PLC, DCS, and other computer control systems.

Therefore, when measuring low-viscosity oils, such as diesel, edible oil, etc., we recommend that turbine flowmeters be considered first.

Extended reading: What Is Hydraulic Flow Meter?

Grease Flow Meters-Gear

Gear flow meter is a micro digital positive displacement flow meter. Can measure very small flow rates and quantify small volumes of liquid. High and low-temperature resistance (-196℃-200℃).

The Gear flow meter for Microflow is made of stainless steel and is used for precise continuous or intermittent measurement of the flow or instantaneous flow of liquid. It is especially suitable for the flow measurement of heavy oil, polyvinyl alcohol, grease, and other high-viscosity media. It can measure the viscosity of Fluid up to 10000Pa.s.

• High pressure resistance (1.0-45MPa)
• High and low temperature resistance (-196℃-200℃)
• Can measure various viscous media
• High precision and repeatability
• Pulse output/analog output optional
• Wide range ratio (1:100)
• Wide measuring range
• Strong anti-corrosion and anti-fouling ability (acid and alkali)

Therefore, it is recommended to use Gear flow meters, when you need to measure grease in the following situations:High viscosity, low flow rate;Ultra-high temperatureUltra-low temperature;Small caliber;high pressure.

Extended Reading: Types Of Crude Oil Flow Meters

Grease Flow Meters-Mass

Mass flow meter directly measures the mass flow of the medium passing through the flow meter. It can also measure the density, temperature, and viscosity of the medium

Mass flow meter is a flow measuring instrument that measures the mass flow in the pipeline. The volume of a fluid is a function of fluid temperature and pressure and is a dependent variable. The quality of a fluid is a quantity that does not change with time, space temperature, and pressure. More about: What Is Mass Flow Rate?

The mass flow meter has high accuracy. But the price is expensive. Therefore, when you need high-precision measurement, you can choose to use a mass flow meter.

Extended reading: Fuel Flow Meter for Boat-Selection & Application

Tool: Volumetric Flow Rate & Pipe Diameter to Flow Speed Calculator

Find the most appropriate industrial grease flow meter from Sino-Inst for a variety of engineering and industrial purposes. Suitable for various fluids with different pressures and volumes. The choice of these depends on whether the volumetric or mass flow rate is to be measured. Grease flow meters offered on the site have wide minimum and maximum pressure ranges, which is considered to be a desirable quality as they can be used for a wider variety of fluids. These grease flow meters are highly accurate.

Explore Oil and Gas Flow Meters

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Extended Reading: Guide and Selection for Diesel Fuel Flow Meters

KimGuo11

Wu Peng, born in 1980, is a highly respected and accomplished male engineer with extensive experience in the field of automation. With over 20 years of industry experience, Wu has made significant contributions to both academia and engineering projects.

Throughout his career, Wu Peng has participated in numerous national and international engineering projects. Some of his most notable projects include the development of an intelligent control system for oil refineries, the design of a cutting-edge distributed control system for petrochemical plants, and the optimization of control algorithms for natural gas pipelines.

drurylandetheatre.com

What is the K-factor in a flow meter?

K-factor is a coefficient calculated by calibrating and comparing with other measuring devices that meet the accuracy requirements. The Flow Meter K-factor will be confirmed before it is put into use.

This coefficient is a fixed value. It is the actual coefficient obtained by the flowmeter manufacturer after verifying each instrument. Nothing to do with the initial design

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The flow coefficient of the flowmeter refers to the proportional relationship between the measured flow and the flow of the standard device under certain conditions. The Flow Meter K-factor is given by the manufacturer when it is calibrated.

The K value is easily immobile. Therefore, as a manufacturer, we generally set a password for the flowmeter.

Flow meter k-factors

Turbine flow meter k-factor

Liquid Turbine Flow Meter is a speed-type flow meter based on the principle of torque balance.

The fluid flows through the sensor housing. Because the blades of the impeller have a certain angle with the flow direction. The impulse of the fluid makes the blades have a rotational torque. After the friction torque and fluid resistance are overcome, the blades rotate. The speed is stable after the torque is balanced.

Under certain conditions, the speed is proportional to the flow rate.

Due to the magnetic permeability of the blade, it is in the magnetic field of the signal detector (composed of permanent magnets and coils). The rotating blade cuts the magnetic lines of force. The magnetic flux of the coil is periodically changed. Electrical pulse signals are induced at both ends of the coil.

This signal is amplified and reshaped by an amplifier. A continuous rectangular pulse wave with a certain amplitude is formed. It can be transmitted to the display instrument remotely. The instantaneous flow or total amount of the fluid is displayed.

Within a certain flow range, the pulse frequency f is proportional to the instantaneous flow Q of the fluid flowing through the sensor. The flow equation is:

Where:
f——Pulse frequency [Hz]
k——The meter coefficient of the sensor [1/m3], which is given by the calibration sheet.
Q——The instantaneous flow of fluid (under working condition) [m3/h]
3600-conversion factor in seconds

The meter coefficient of each sensor is filled in the verification certificate by the manufacturer. The k value is set in the matching display instrument. The instantaneous flow and cumulative total can be displayed.

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Vortex flow meter k-factor

Vortex flowmeter is a speed-type flowmeter produced according to Karman’s vortex principle,
which can be used for the measurement and measurement of conventional gas, steam and
liquid.

Vortex flow sensor has high precision and wide range ratio, no moving parts in use, which can
improve mechanical stability and reduce maintenance. Vortex flowmeter is almost not affected by the temperature, pressure, and composition of medium when measuring the volume of working conditions.

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Therefore, it is convenient to calibrate the instrument, so the vortex street flow sensor is widely used in production and life.

When a trigonal column vortex generator is set in the fluid, regular vortices are generated alternately on both sides of the vortex generator, which is called Carmen vortex.

The vortex columns are arranged asymmetrically downstream of the vortex generator. Vortex flowmeter is produced according to this principle.

Vortexes are generated by generating bodies and the number of vortexes is detected by high-sensitivity sensors. In a certain range, the number of vortexes generated is proportional to the flow rate.

In vortex flowmeter, the relationship between flow rate and the number of vortexes generated
can be expressed by the following formula：

Q：Operating volume flow of the measured medium. The unit is m3/h。
F：Frequency of the number of vortices produced by the generating body. The unit is Hz.
K：Refers to the calculated or calibrated flow coefficient. It represents how many frequency signals per cube. the coefficient is usually obtained by calibration.

The formula of standard table method calibration coefficient K:

The formula can also be used for flow correction.

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Gear flow meter k-factor

K coefficient of gear flow transmitter (flow coefficient) defines the number of impulses per L within the unit flow precisely.

The following formula is used:

Q=f×60/K

Q=Instantaneous flow L/min
F=Frequency of output impulse(HZ)
K= Coefficient of gear flow meter(impulse/min)

Read more General-purpose Flow Totalizer for Data collection and calculation

K-Factors calculation

1.What is a K-factor?

Simply stated a K-factor is a dividing factor. The term is usually encountered when dealing with pulse signals although analog K-factors are sometimes used.

2. Pulse Signal K-factors

All pulse output type flow meters when they are dispatched by their manufacturer will have a calibration certificate. The calibration certificate will show that the meter has been calibrated over its flow range and noted on the certificate will be the average K-factor for the meter.

This K-factor will be given in terms of the number of pulses produced by the meter for a given volumetric flow. (e.g.) 200 pulses per U.S. gallon, 150 pulses per liter, etc.

This K-factor is the value that is entered into a batch meter or indicator/totalizer in order to give a readout in engineering units.

Example 1

If the display on a rate meter is required in U.S. gallons per second, and the K-factor of the flow meter is 210 pulses per U.S. gallon, then the K-factor entered into the rate meter would be 210.

If a totalizer associated with the same flow meter was to be set up so as to totalize in U.S. gallons the totalizer K-factor would be 210.

If the totalizer was to be set to totalize in tenths of a gallon the K-factor would be 210/10 = 21

Example 2

If the display on a rate meter is required in U.S. gallons per minute, and the K-factor of the flowmeter is 210 pulses per U.S. gallon, then the K-factor entered into the rate meter would be: 210/60 = 3.5

3.K-factors for Analog Input Signals

When batching, indication or totalization has to be carried out using an analog input signal a KEP product first converts the 4 to 20 mA signal into a 0 to 10000 Hz. signal. The K-factor is then calculated by relating the engineering unit equivalent of 20 mA to the 10000 Hz. signal.

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Example 3

A vortex meter outputs 20 mA when the flow is 2000 U.S. gallons per minute, we wish to display the rate in gallons per minute.
The rate K-factor is = 10000/2000 = 5

The value of the totalizer K-factor will depend on whether the flow rate was given in units per second, a minute, or hour and whether it is desired to totalize in whole units, tenths, hundredths, etc.

If the flow rate was given in units per second the totalizer K-factor (for whole units) is obtained by multiplying the rate K-factor by 1.

If the flow rate was given in units per minute the totalizer K-factor (for whole units) is obtained by multiplying the rate K-factor by 60.

If the flow rate was given in units per hour the totalizer K-factor (for whole units) is obtained by multiplying the rate K-factor by 3600.

The totalizer K-factor in example 3 will be = 5 x 60 = 300 in order to totalize in gallons.

If we wished to totalize in tenths of a gallon the K-factor would be 5 x 60/10 = 30

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Example 4

An electromagnetic flow meter outputs 20 mA when the flow is 20 liters per second, we wish to display the flow rate in liters per second and totalize in M³.
The rate K-factor is 10000/20 = 500
The totalizer K-factor will be 500 x 1/0.001 = 500000

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4.Multi-Point K-factors

Some flow applications dictate that multiple K-factors are used. Two applications that require multiple K-factors are:

• flow meters with nonlinear outputs
• wide turndown flow applications

KEP meters have an option available that allows the user to input from 3 to 16 K-factors. This multi-point K-factor option is available for both pulse and analog inputs.

5.Multi-Point K-factors for Pulse inputs

The first step is to calculate K-factors to cover each flow range. This is done by taking the information on the flow meter manufacturer’s calibration sheet and calculating the K-factors as per section 2. An alternative to using the manufacturers’ data is to conduct tests on-site against a calibrated standard.

The second step is to relate an incoming frequency range from the flow meter to a given calculated K-factor.

The final step is to program these values into the KEP instrument.

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Example 5

A turbine flow meter has the following calibration data.

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6.Multi Point K-factors for Analog Inputs

The procedure for analog inputs is essentially the same as for pulse inputs.

The first step is to calculate K-factors to cover each flow range. This is done by taking the information on the flow meter manufacturer’s calibration sheet and calculating the K-factors as per section 3. An alternative to using the manufacturer’s data is to conduct tests on site against a calibrated standard.

The second step is to relate an incoming flow value from the flow meter to a given calculated K-factor.

The final step is to program these values into the KEP instrument.

Example 6

A vortex flowmeter has the following calibration data.

Base K-factor 10000/100 = 100

Note that the point after the final one should have a flow value entered that is very much higher than the true maximum flow rate of the meter. Note also that as the last two K-factors are the same any flow above 100 gpm will be modified by a K-factor of 104. The setup is now complete.

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You may like:

Sino-Inst offers over 50 flow meter for flow measurement. About 50% of these are differential pressure flow meters, 40% is the liquid flow sensor, and 20% are Ultrasonic flow Transmitter and mass flow meter.

A wide variety of flow meters options are available to you, such as free samples, paid samples.

Sino-Instrument is a globally recognized supplier and manufacturer of flow measurement instrumentation, located in China.

KimGuo11

Wu Peng, born in 1980, is a highly respected and accomplished male engineer with extensive experience in the field of automation. With over 20 years of industry experience, Wu has made significant contributions to both academia and engineering projects.

Throughout his career, Wu Peng has participated in numerous national and international engineering projects. Some of his most notable projects include the development of an intelligent control system for oil refineries, the design of a cutting-edge distributed control system for petrochemical plants, and the optimization of control algorithms for natural gas pipelines.

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