The height of the liquid medium in the container is called the liquid level, and the instrument for measuring the liquid level is called the liquid level gauge. Liquid level gauge is a kind of level instrument.
The type of liquid level gauge includes tuning fork vibration type, magnetic suspension type, pressure type, ultrasonic wave, sonar wave, magnetic flip board, radar, etc.
Level Measurement
A new level of experience in all of your applications.
Built on global experience in the field, Siemens provides a complete range of level measurement devices for every application. With the knowledge that no single technology can address the needs of all industrial challenges, Siemens offers a full range of contacting and non-contacting instrumentation for continuous and point level level measurement. This is what experience buys: installing Siemens level technology is like sitting beside the smart kid in class. The kid who has done the homework, been to all the lessons. Choose experience. Choose Siemens level.
The following is the product model and its introduction：
7ML1201-1EF00, 7ML1201-1EE00, 7ML1201-2EE00, 7ML1201-1EK00, 7ML1201-1AF00, 7ML5221-1BA11, 7ML5221-1AA11, 7ML5221-1BA12, 7ML5221-1AA12, 7ML5221-1DA11, 7ML5221-1CA11, 7ML5221-1DA12, 7ML5221-1CA12, 7ML5033-1BA00-1A, 7ML5033-1BA10-1A, 7ML5033-2BA00-1A, 7ML5033-2BA10-1A, 7ML5004-1AA10-3B, 7ML5004-2AA10-3B, 7ML5007-1AA00-2A, 7ML5810-1A, 7ML1106-1AA20-0A, 7ML1115-0BA30, 7ML1115-1BA30
1. Point Level Measurement
Your plant’s lifeline to safety, efficiency, and a headache-free day.
Modern point level technology plays a number of critical roles in your operations – either in partnership with other instrumentation or on its own. Backup alarming to material presence detection and/or point level monitoring, protection against running empty, or a cost-effective choice for material detection – Siemens' range of point level devices covers it all. Capacitance, ultrasonic, rotating and vibrating level switches are suitable for virtually all applications from bulk solids to liquids, and everything in between.
Siemens Point Level Advantage
Siemens point level portfolio includes capacitance, ultrasonic, rotary paddle, and vibrating level technology for everything from highly sensitive applications to the most rugged environments. With their easy installation and integration into your control system, these long-lasting devices reduce your maintenance costs, no matter the application or material.
1) Capacitance
Our comprehensive portfolio features a range of technologies that provide extremely reliable and precise point level detection. The level switches offer superior performance while reducing maintenance, downtime, and equipment replacement cost. Their robust aluminum or chemically resistive plastic enclosures last in harsh and abrasive environments, guaranteeing a long service life and low cost of ownership. With a selection of options including PROFIBUS communications, digital displays, remote or local testing, and functional safety SIL2, improved safety and integration into your plant's operations has never been easier.
Foam, liquids, bulk solids applications, and interface can all be easily monitored by our switches.
The best-in-class inverse frequency shift approach to RF capacitance technology ensures accurate, reliable, and repeatable measurement, even in dusty, turbulent, and vaporous environments or in situations with product buildup. Because even a small level change creates a large and detectable change in frequency, Siemens Pointek CLS series provides excellent resolution while consistently outperforming conventional devices.
Pointek CLS100 is the compact universal switch for constricted spaces. Pointek CLS200 is the standard universal switch with a wide range of communications and probe extensions and the Pointek CLS300 is for harsh, demanding applications with high temperatures and pressures.
2) Rotary Paddle
One of the only paddles available with functional safety SIL2 options, SITRANS LPS200 rotary paddle switch is world-class for reliable and safe point level detection in bulk solids. Its rugged design combined with motor stop technology and rotation failure detection means that you can expect reliable and safe measurements every time. With a wide variety of paddle options available, there is a switch suitable for most applications.
3) Ultrasonic
Siemens non-contacting ultrasonic level switch is ideal for level detection of bulk solids, liquids and slurries in a wide variety of industries.
4) Vibrating
Siemens vibrating level switches are perfect for detecting high, low, and demand levels in liquid or solid applications including materials with extremely low bulk density. With options for high temperatures, extreme pressures, and remote testing, these switches provide solutions for most industries.
SITRANS LVL200 is designed to measure difficult applications, providing immunity to turbulence, foam, bubbles, and external vibrations for all liquids and slurries. These switches are perfect for pump protection applications and are suitable for most aggressive and hazardous environments. In advanced ingress protection applications, they can provide a second line of defense, keeping your processes protected. SIL2 and optional remote testing via a signal conditioner or direct from the control system ensure increased safety and reliability.
SITRANS LVL100 is the compact version for non-sticky, non-hazardous liquids and slurries, and features short insertion and user friendly connection options.
SITRANS LVS100 and LVS200 are for dry powder solids. SITRANS LVS100 is designed for bulk solids with densities starting at 30 g/l (1.9 lb/ft3) and SITRANS LVS200 is for even lower densities as low as 5 g/l (0.3 lb/ft3). SITRANS LVS200 series has potted electronics and a robust design for aggressive applications including heavy external vibrations.
2. Continuous Level Measurement
The continuous eyes and ears of your operations.
Processes in your facility are constantly changing – so you’d better know what’s where and how much you have, at all times. The answer? Siemens continuous level measurement, featuring a full range of technologies for your exact application: ultrasonic, radar, guided wave radar, capacitance, gravimetric and hydrostatic. With intuitive setup, world-class accuracy and a global network of support. Always monitoring, always precise, always from Siemens.
1) Radar level measurement
Real intelligence built on experience – see the difference
When it comes to radar level measurement, it’s time to ask: what does a device’s experience offer your operations? What will make your job easier, not harder? In the case of Siemens radar transmitters, experience means answers to challenging conditions that other technologies - and our competitors’ devices - can’t handle. Our signal processing technology for level instruments is based on the experience of over a million instruments worldwide. With Siemens radar technology, this experience means managing materials and optimizing inventory ordering to use these resources more effectively, increasing efficiency and saving you money.
2) Guided wave radar level measurement
Reliable installation, little to no configuration – radar that just works.
Four models make up the series of Siemens guided wave radar – your experts for a world of applications. For measuring interface or level, Siemens guided wave radar does what you need it to do – in the easiest applications to the most demanding. Quick and easy setup with local four-button programming and menu-driven quick start wizard gets you operational in minutes, saving you time and money. Plus, the unit comes pre-configured to fit your application needs, so there’s typically no setup onsite required.
3) Ultrasonic level measurement
Field-proven in more than a million applications worldwide
Across the globe, Siemens ultrasonic level devices can be found in nearly every market. And there’s a reason why they continue to be industry standard for so many applications. Accuracy. Price point. Durability. Ease of use. As the world's leading provider of ultrasonic level measurement technology, Siemens offers a wide selection of devices, from user-friendly and highly reliable transmitters, a broad portfolio of controllers, and a range of transducers.
4) SITRANS LC300
SITRANS LC300 is an inverse frequency shift capacitance continuous level transmitter for liquids and solids applications. It is ideal for standard industrial applications in chemical, hydrocarbon processing, food and beverage and mining, aggregate and cement industries. SITRANS LC300 is a 2-wire level measurement instrument combining a sophisticated, yet easy-to-adjust microprocessor with field-proven probes. It is available in two versions: rod and cable. SITRANS LC300 has a stainless steel process connection with PFA-lined probe. Materials with low or high dielectric properties are accurately measured and Active-Shield technology helps in ignoring the effects of buildup near vessel nozzle.
5) Hydrostatic level measurement
Low-cost and hard wearing.
Siemens offers a comprehensive product portfolio for hydrostatic level measurement -whether by direct measurement or remote seals, whether on open or closed containers. Our SITRANS P pressure/differential pressure transmitters are extremely resistant to chemical and mechanical loads as well as electromagnetic interference and are commonly used in the chemical and petrochemical industries. As well, don’t forget that the safest engineered level measurement solution includes switches for back-up, overfill, low level and dry run protection
3. Interface level measurement
Mixing application versatility with proven results – no matter the industry
Whether it’s water and oil or two wildly different chemicals, some things just don’t mix. Luckily, Siemens interface technology measures level of multiple materials with ease and precision. Capacitance and guided wave radar technology provide results-driven level measurement in all your interface applications, giving you the accuracy and continuous monitoring to keep operations running smoothly throughout the day. Interface measurement easily handles changing pressure and temperature conditions and is unaffected by vapor or condensation. Whether measuring levels of two materials in a storage vessel or telling your control system when to separate one liquid from another, accurate monitoring helps ensure product quality and an efficient process.
1) Point level liquids interface - capacitance
Our comprehensive portfolio features a range of technologies that provide extremely reliable interface detection. The level switches offer superior performance while reducing maintenance, downtime, and equipment replacement cost. Their robust aluminum or chemically resistive plastic enclosures last in harsh and abrasive environments, guaranteeing a long service life and low cost of ownership. With a selection of options including PROFIBUS communications, digital displays, remote or local testing, and functional safety SIL2, improved safety and integration into your plant's operations has never been easier.
The best-in-class inverse frequency shift approach to RF capacitance technology ensures accurate, reliable, and repeatable measurement, even in dusty, turbulent, and vaporous environments or in situations with product buildup. Because even a small level change creates a large and detectable change in frequency, Siemens Pointek CLS series provides excellent resolution while consistently outperforming conventional devices.
Pointek CLS100 is the compact universal switch for constricted spaces.
Pointek CLS200 is the standard universal switch with a wide range of communications and probe extensions.
Pointek CLS300 is for harsh, demanding applications with high temperatures and pressures.
2) Point level or solids interface - vibrating
Siemens vibrating level switches are perfect for detecting high, low, and demand levels in liquid or solid applications including materials with extremely low bulk density. With options for high temperatures, extreme pressures, and remote testing, these switches provide solutions for most industries.
SITRANS LVS200 can detect a solids interface within a liquid. With potted electronics and a robust design for aggressive applications including heavy external vibrations.
3) Continuous interface or level - capacitance
Capacitance instruments are contacting level and interface devices for measuring liquids and some solids. Inverse frequency change technology delivers high resolution, fast reaction time, and consistently accurate measurements of even the smallest level changes, in short spans, or in materials with a low dielectric constant (dK). With simple two-button start-up and extremely low maintenance and recalibration needs, capacitance technology will save you time and money.
SITRNS LC300 is ideal for standard and industrial applicaitons in the chemical, hydrocarbon processing, and food and beverage industries and can handle those difficult applications where emulsion and rag layers are challenging.
4) Continuous interface and level - guided wave radar
Guided wave radar is a contacting technology that excels in monitoring interface of liquids and also provides accurate level measurement. One instrument, two measurements. Advanced echo processing gives you unmatched reliability and accuracy when measuring level and interface in everything from small to large vessels. Extreme conditions like high pressure and vapors are no problem for these transmitters. With easy to use quick start wizards for setup, field replaceable and adjustable probes for easy maintenance, and SIL ratings for safe operation, see the difference guided wave radar makes.
Features:
The stability is good, and the long-term stability of full scale and zero position can reach 0.1% FS / year. In the compensation temperature range of 0 to 70 ℃, the temperature drift is less than 0.1% FS, and it is less than 0.3% FS in the entire allowable operating temperature range.
With reverse protection and current limiting protection circuit, the reverse connection of positive and negative poles during installation will not damage the transmitter. When abnormal, the transmitter will automatically limit the current within 35MA.
Solid structure, no moving parts, high reliability and long service life.
Easy installation, simple structure, economical and durable.
Performance characteristics:
Its mechanical structure is highly resistant to overload and corrosive media
High-precision, long-term stable ceramic capacitor and imported diffused silicon measurement unit
Sealed electronic module and dual-filter pressure compensation system can resist the impact of climate field changes
The electronic module can output 4 ... 20mA signal and at the same time with overvoltage protection module
Select the integrated temperature sensor Pt100 for simultaneous level and temperature measurement
Corresponding accessories can provide a complete measurement program
Float level transmitters are widely used in oil refining, chemical, paper, food, and sewage treatment industries. It can display, alarm and control the medium liquid level in openings, closed containers or underground tanks in the instrument control room. The detected medium can be conductive and non-conductive liquids such as water, oil, acid, alkali, industrial sewage, etc., and can overcome the effect of the false liquid level caused by the liquid foam.
Precautions:
The correct selection of the liquid level gauge can guarantee the better use of the liquid level gauge. What kind of liquid level meter should be determined according to the physical and chemical properties of the measured fluid medium? Make the liquid level meter's diameter, flow range, lining material, electrode material and output current, etc. can be adapted to the measured fluid Requirements for nature and flow measurement.
1. Precision function check
Accuracy level and function Select the accuracy level of the instrument according to the measurement requirements and application occasions to achieve economical and cost-effective. For example, for trade settlement, product transfer and energy measurement, you should choose a higher accuracy level, such as 1.0, 0.5, or higher; for process control, choose different accuracy levels according to control requirements; some only It is the occasion to check the process flow without precise control and measurement. You can choose the lower accuracy level, such as 1.5, 2.5, or even 4.0. At this time, you can choose a low-cost plug-in level gauge.
2. Measurable medium
Measuring medium flow rate, instrument range and caliber When measuring general medium, the full-scale flow of the liquid level gauge can be selected within the range of measuring medium flow rate 0.5-12m / s, and the range is relatively wide. The specifications (caliber) of the selected instrument are not necessarily the same as the process pipeline. It should be determined according to whether the measurement flow range is within the flow rate range, that is, when the pipeline flow rate is too low to meet the requirements of the flow meter or the measurement accuracy cannot be guaranteed at this flow rate The caliber of the instrument needs to be reduced, so as to increase the flow velocity in the pipe and obtain satisfactory measurement results.
With the continuous development of industry, liquid level sensors are used in more and more industries. When using transmitters, we need to pay attention to some issues, which not only makes our measurements more accurate, but also enables our The service life of the liquid level sensor is longer. Take a look at what you need to pay attention to:
1. Do not add a voltage higher than 36V to the transmitter, otherwise the transmitter will be damaged;
2. Do not touch the diaphragm with hard objects, otherwise the isolation diaphragm will be damaged;
3. The medium measured by the liquid level sensor is not allowed to freeze, otherwise it will damage the isolation diaphragm of the sensor element and cause damage to the transmitter. If necessary, the transmitter must be temperature-protected to prevent freezing;
4. When measuring steam or other high-temperature media, the temperature should not exceed the limit temperature when the liquid level sensor is used, and the heat sink must be used above the limit temperature used by the variable liquid level sensor;
5. When measuring steam or other high-temperature media, a heat pipe should be used to connect the liquid level sensor and the pipeline, and the pressure on the pipeline is used to transmit it to the transformer. When the measured medium is water vapor, an appropriate amount of water should be injected into the heat dissipation tube to prevent the superheated steam from directly contacting the liquid level sensor and damaging the sensor;
6. In the process of pressure transmission, the following points should be noted,
A. The connection between the liquid level sensor and the heat dissipation tube must not leak air;
B. Before starting to use, if the valve is closed, you should open the valve very carefully and slowly to avoid the measured medium directly impacting the liquid level sensor diaphragm, which will damage the sensor diaphragm;
C. The pipeline must be kept clear, the sediment in the pipeline will pop up, and damage the sensor diaphragm.
The internal floating magnetic liquid level gauge is a dual-chamber liquid level gauge. The measured medium is isolated from the cavity at the end of the magnetic panel. The interior of the container end cavity and the float are specially treated to ensure that the float is linearly transmitted with the change of the liquid level. Give the magnetic panel and indicate the height of the liquid level clearly and accurately. It can be displayed on site, taking into account the alarm control and output remote transmission signals. It is a multi-function liquid level measuring instrument. Magnetostrictive liquid level gauges are widely used in industrial process control, petroleum processing, pharmaceuticals, food processing, water treatment, gas stations, grinding machinery, valve opening control and other physical parameters such as liquid level, temperature, density, interface conditions Monitoring, alarm and control.
