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Posted on 12/01/11, under Customer Expertise, Industries, Information, Instrument Ranges, Measurement Principles, PACTware Training, VEGA Service, VEGA Training · RSS · No Comments
The PACTware Seminars for 2011 have been confirmed!
The training dates for this year:
* 30th March * 8th June *
* 5th October * 24th November *
All courses will be held at VEGA Head Office in Burgess Hill, West Sussex
Course Costs:
£240 or £340 with overnight stay
Did you know we also provide onsite courses, tailored specifically to your requirements? The difference in cost is negligible and will save your staff time and the inconvenience of travel.
Posted on 03/12/10, under Application News, Chemical, Hydrostatic, Information, Level Interface, Offshore Oil & Gas, Petrochemical, Pharmaceuticals · RSS · No Comments
Interface level is generally a difficult measurement to make and there are merits for all the devices currently provided by VEGA (eg TDR, Nucleonic, Capacitance, Differential Pressure). However there are occasions where mechanical installation, the electrical properties or SGs of the products force us to look for more subtle solutions.
Multi-technology interface level
If we take the example of a high Dk product forming an interface on top of another high Dk product we cause problems for a TDR and Capacitance. If our measurement needs to be top mounted with no side access we start the create similar problems for DP and Nucleonics. This opens the door for looking at using a time of flight device alongside a suspended hydrostatic sensor.
To measure the interface using these sensors we need to appreciate that while they will both give accurate measurement of level, one is directly measuring volume while the other is measuring weight (or hydrostatic head). If we were to calibrate them on the same product ie water with an SG of 1 they will give the same output. However if a lower SG product is introduced ie Oil with an SG of 0.87 to form an interface, we would have an discrepancy in the 2 readings and this difference is what we will span to give our interface.
The volume measurement can be made by a number of different techniques (eg Radar, Ultrasonic, TDR) the only criteria is that the range it is calibrated for is the same as the hydrostatic head we are measuring. The Hydrostatic sensor calibration is also relatively easy, but the SG of both products must be known and remain consistent to provide an accurate measurement. We simply calibrate this device with only the lighter product present up to 100% and set our device to 4mA. We now repeat the process with only the heavier product now present and calibrate the 20mA value.
We now require to take both inputs into a (PLC or Signal Conditioner) and subtract the inputs to give us the distance to our interface.
If you would like more information on the above blog please contact us on the details below.
Posted on 01/11/10, under Information, VEGA Events · RSS · 1 Comment
VEGA Wear it PINK!!!
Taking a break from their work providing level and pressure measurement solutions for industry, VEGA staff got busy with wear it pink day, raising money for breast cancer research. Thanks for all your kind donations!
Posted on 25/08/10, under Aggregates & Mining, Application News, Bulk Solids Handling, Bulk Solids Measurement, Cement, Environment & Recycling, Exhibitions, Level Measurement, Nucleonics, Radar, VEGA Product News · RSS · No Comments
Non-Contact Level and Mass Flow Measurement and Control with Microwave and Radiometric based Instruments in Solids Handling – PART 1
Mr. Doug Anderson, Mr. Graeme Cross, Mr. Gary Baker
Abstract
Solids handling offers many challenges for measurement and control. The product properties are the most major – dust abrasion, impacts, bulk density, material flow and movement. These all have an impact on the type of handling equipment, as well as the measurement and control systems that say “when” and “how much”, no matter what parameter is being measured. Many measurement systems incorporate mechanical parts or movements, which require contact with the product or process. By using non-contact devices, the ease of implementation, and improvement to lifespan and reliability can outweigh any price difference, should there be one.
Introduction
This paper looks at 2 areas in particular, level and mass flow measurement, to explore the options for some applications, particularly for difficult to handle product or difficult to measure situations. These are not definitive for all applications, but some alternative ideas, with application examples, to show other ways these have been solved, to increase reliability and productivity, saving space and downtime for some difficult to measure areas.
Factors to consider for level measurement of solids
The product to be measured and the accuracy required, are the first considerations for a system.
A silo weighing system may be more suitable for the application, whenever it is practicable and affordable to use one, especially on a new installation, they are normally the first choice.
However this is not always suitable, and some of these considerations will also help decide. The elements to factor in for a measurement application is the type of vessel, what the surface area and profile is likely to be like for a representative level measurement, what the vessel is manufactured from, and the top and bottom forms, outlet and roof structures etc. These will have an affect on the performance of a measurement system.
Process conditions for measurement
If a vessel is to be measured, the filling stream and type has to be taken into account. Dust, air conveying, filling noise and turbulence will all play a role.
When the vessel is emptying, will there be bridging or rat-holing? If the vessel is ‘zeroed’ or ‘tared’ on a weigh cell system, because there is ‘nothing coming out’, what are the consequences if there are still tons of material inside? Temperature of the incoming product and pressure inside the vessel, particularly if it is high, also play a part.
Mechanical, product and safety
Mechanical forces exerted by the product, for example if a cable based level device is used and it is a mass flow silo, will there be a significant loading on the roof of the vessel, or will corrosion/abrasion cause wear to any devices in contact with the process. Could the product build-up significantly on the vessel or on the measurement probe. Finally there are the safety considerations, is ATEX for combustible dust and ignitable gases etc. required and what are the consequences should the vessel overfill?
PART 2 coming soon….
If you would like more information on the above blog please contact us on the details below.
Factors to consider for level measurement of solids
Posted on 13/08/10, under About VEGA, Aggregates & Mining, Bulk Solids Handling, Cement, Environment & Recycling, Exhibitions, Information, Instrument Ranges, Measurement Principles, VEGA Events · RSS · No Comments
Bulk Solids Europe 2010
International Conference on Storing, Handling and Transporting Bulk.
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