VEGASWING: For manifold applications in liquids

Measuring principle and applications

The piezo drive is the heart of the sensor, activating the tuning fork to vibrate on its resonance frequency. The frequency of the fork reduces with the immersion. The frequency change is evaluated by the integrated electronics and converted into a switching signal. An optimized screwed connection is used to ensure reliability and ruggedness of the piezo drive. With the tuning fork of only 40 mm length, VEGASWINGs work reliably in all liquids independent of the installation position. Pressure, temperature, foam, viscosity and bubbles do not influence the switching accuracy.

VEGAVIB: Reliable switching in bulk solids

Measuring principle and applications
The vibrating rod of VEGAVIB is activated to vibrate via the piezo drive. If the vibrating rod is immersed, the amplitude will be damped. The electronics detects this damping and converts it into a switching command.

Due to the rod design, it is almost impossible for material to build up or get wedged in. The easy cleanability offers the requirements for use in the food processing and pharmaceutical industry. The installation position and granulation size do not influence the reliability. Mounting and setup are very easy, an adjustment with medium is not necessary. Typical applications are overfill and dry run protection systems in products such as plastic granules, styrofoam, milk powder and pellets.

VEGAWAVE: Robust and reliable

Measuring principle and applications

A tuning fork is used as sensor for the VEGAWAVE series. Control as well as processing correspond to VEGAVIB series.

The advantages of this series are ruggedness as well as insensitivity to buildup. Therefore, it is the ideal sensor for powders and fine-grained products. Mounting and setup are very easy, an adjustment with medium is not necessary. Typical applications are overfill and dry run protection systems in products such as flour, cement, plastic granules, sand fine gravel and styrofoam.

The proven capacitive measuring principle is one of the most common measuring principles for level measurement in the industrial measurement technology. Sensor and vessel form the two electrodes of a capacitor. A capacitance change caused by a level change is processed by the integrated electronics and converted into a switching signal. The level measurement is carried out via the complete sensor length without a dead zone. Thanks to cable and rod versions, suitable instruments are available for all applications.

Applications in liquids
Mainly fully insulated instrument versions are used in these applications. Hence measurements of corrosive liquids or adhesive products are no problem. The mounting of the instruments is easy and the rugged construction is the basis for an interference and maintenance free operation. 

Applications in bulk solids
Partly insulated versions are preferably used in bulk solids. Also here, we have the proven, rugged configuration as basis for the manifold and reliable use, e.g. in the aggregates and mining industry.

Short ultrasonic impulses in to range of 10 to 70 kHz are emitted by the transducer to the measured product, reflected by the product surface and received again by the transducer. They spread with sound velocity. The time from emission to reception of the signals is proportional to the level in the vessel. The proven ECHOFOX signal processing filters out the correct level echo reliably from a number of false reflections. An adjustment with empty and full vessel is not necessary!

Application in liquids
Sensors with frequencies between 30 and 70 kHz are used for these applications. They operate independent of product properties and are ideal for water/waste water applications and the measurement of slightly corrosive acids and lyes. Also applications in gas-Ex areas can be equipped with these sensors. 

Applications in bulk solids
Sensors with frequencies between 10 to 30 kHz are used for these applications. The lower switching frequency enables a considerably better penetration of dusty atmosphere. An adjustment with medium is not necessary. For applications in dust-Ex areas, approved sensors are available.

Applications in liquids
Density fluctuations, steam generation or strong pressure and temperature fluctuations do not influence the measuring result. Also buildup on the probe or the vessel wall do not influence the measurement. An ideal application is level measurement in a bypass tube where even products with dielectric values below 1.6 can be measured reliably. Also connection tubes - bypass tubes have no influence.

Applications in bulk solids
Typical problems in bulk solids such as e.g. dust and noise generation or condensation do not influence the reliability. Also the shape of the material cone or the product properties, e.g. the change from dry to wet sand do not influence the measuring result. Since the instruments are already preadjusted, setup is limited to connection of the sensor.

Radar level sensors work with safe, low emitted power in the C and K-band frequency range. The proven ECHOFOX signal processing selects the correct level echo reliably. Adjustment by filling and emptying the vessel is not necessary, it can normally be done with simple input of vessel dimensions.

Applications in liquids
Two different emitting frequencies are available for these applications. The compact, high frequency sensors are particularly suitable for applications for which high accuracy is required. Even with small antenna sizes, an excellent signal focusing is reached. Low frequency C-band sensors can penetrate foam and strong condensation and are thus particularly suitable for arduous process conditions. Unaffected by steam, gas composition, pressure and temperature changes the sensors detect the product surface of different products reliably.

Applications in bulk solids
High frequency sensors in K-band technology are used for these applications. Thanks to the very good focusing of the signals, the influences of silo installations or buildup on the vessel wall are gated out. A high sensitivity electronics adapted to the requirements of the bulk solids measurement, enables a reliable level measurement of different products up to 70 m. The measuring principle is unaffected by strong dust generation, filling noise, air turbulence by pneumatic filling and temperature fluctuations. The application area covers applications in the food processing industry and the plastic processing up to the steel generation.

PRESSURE MEASUREMENT 

Pressure is a really important measurement to monitor and check, as the consequences of inadequate measuring systems in place could be catastrophic, especially as so many industries have pressure related processes.  Industries need pressure monitoring systems in place to make a certain pressure has been met, that is pressure is constant, or to ensure pressure is not exceeded.   Through reliable pressure instrumentation, accurate and automated information will ensure safety, productivity, quality, economy and efficiency in modern day manufacturing. 

An example of where pressure measurement is carried out is when a diaphragm is deflected by a product, like gas.  This deflection is tiny, so an accurate consistent measurement of this movement is essential, especially when the gas (or other product) will expand or contract with minor temperature variations, therefore having a significant influence. 

We have established the importance of reliable level pressure instruments - the selection of the correct type of sensor is just as important, as aspects like use of chemicals, physical features, temperatures, pressure shocks and pulses must also be taken into consideration.   The following VEGA ranges embrace the pressure measuring principle: 

Hydrostatic - VEGABAR/WELL Range

Process Pressure - VEGABAR Range

Differential Pressure - VEGADIF Range

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LEVEL INTERFACE 

Level interface is caused by the separation of two liquids, the most common being oil and water.  The interface is caused by one of the liquids not being able to mix with the other, possibly because it is a different weight – oil is lighter than water, does not mix well and floats on top of the water Level Interface doesn’t just occur with liquids, because sometimes liquid needs to be separated from solid matter in some processes too.  Interface measurement instruments are used to control the separation of these two products (whether liquids or liquid and solid), and are often the solution used in processing and effluent control. 

The ways in which the interface can be detected are by measuring weight, electrical pulses, and working out the differentials of the products (e.g. oil is lighter, floats and is non-conductive).   VEGA has a range of instruments that detect these differences, either as a switch point, or a continuous measurement of the interface between two liquids, or a solid and liquid.   These ranges are listed below:

Guided Microwave - VEGAFLEX Range

Capacitive - VEGACAP Range

Nucleonic - VEGA OHMART Range

Vibration Solids - VEGAVIB Range

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DENSITY 

If there are changing weights, for a fixed volume, then density measurement is what you need. This will depend on the industry, application and product requirements, for example if you need to reduce the water content to increase concentration, or add heavier solids to the liquid to produce slurry, then this will change the density of the product you want to measure.

Instruments that measure density work by either measuring the weight of an known quantity, or by how the signal conveys the weight – the less of a signal, the more dense, or the more of a signal would be less dense. Obviously, you would need to understand this signal, and automate the process, so you don’t have to sit there and watch it 24/7. These measurements will often ensure the quality of your product.

This measurement principle is widely used for detecting changes in switching and measuring density itself. VEGA have a range of instruments, with different techniques, that detect the differences in density either at a switch point, or as a continuous measurement. These instruments are listed below:

Hydrostatic - VEGABAR/WELL Range

Nucleonic - VEGA OHMART Range

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LEVEL SWITCHING 

Another important control to have in place, for every industry, is the knowledge of when to start and when to stop a process.  If you are emptying, filling, controlling or protecting processes, then you need a reliable and secure level switching solution. 

 Obviously having these switching systems in place is paramount, as any failures, or unnoticed failures, in the aforementioned processes (emptying, filling, controlling and protecting) will cost valuable money and even in some cases affect the environment. 

 It is very important for the correct level switching instrument to be chosen, as there will be a few factors that will influence what switching system you require, like whether there are chemicals involved in the process, or whether it’s a liquids or solids application.   Once again, other considerations in your choice of level switch instrument will include whether there are high pressures, temperatures, build up, foam, dust, vapours, or stirrers. 

VEGA Instruments that fulfil the measuring principle of level switching:

Capacitive - VEGACAP Range

Nucleonic - VEGA OHMART Range

Vibration Solids - VEGAVIB Range

Vibration Liquids - VEGASWING Range

Conductive – VEGA Conductivity Range

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