Posted on 18/04/08, under Principles of Good Measurement, pressure · RSS · No Comments
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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Posted on 17/04/08, under Level Interface, Principles of Good Measurement · RSS · No Comments
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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Posted on 16/04/08, under Density, Nucleonics, Principles of Good Measurement · RSS · No Comments
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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