By Diane Silcock
VEGA Instruments – a global leader in the field of measurement technology – recently exhibited at the Electra Mining show. Their working models were a big attraction with VEGA experts demonstrating to visitors, different types of level and pressure measurement applications including nucleonic level and density detectors.
VEGA Instruments’ product specialist, Clint Viviers, explains: “Our radar sensors can handle any application, whether the medium to be measured is liquid, solid, hot, cold, hazardous or corrosive, but what we demonstrated with one of our working models at Electra Mining, was the measurement of solids and the challenges of dusty areas. In mining, for instance, solid particles fly through the air, creating a dust cloud which customers perceive as a challenge when it comes to level measurement. With our technology, the challenge is overcome because dust does not affect a radar’s measurement, thereby ensuring accurate measurements.”
VEGA’s chemical type liquids display had two separate pressure transmitters connected together via a four-core cable. These transmitters have a robust ceramic diaphragm which is about ten times stronger than alternative technology which has costly, small stainless steel parts that are prone to damage and are high in maintenance, unlike the ceramic type from VEGA.
“With our user-friendly devices,” says Viviers, “the electronics are designed to do all the necessary calculations for different applications. For example, with a differential pressure system, two different pressures are measured on each leg and subtracted from each other so you have more than one variable.
“In a mixing tank with liquids, for instance, it’s easy to measure the water in a vessel but once you add, say a flocculant to get the right concentration, the density will increase, thereby driving the pressure reading higher. Using a single device will not result in an accurate measurement when the density changes. However, with electronic differential pressure, by selecting the application of density compensated level, we are compensating for density fluctuations and can give the accurate level measurement as well as the density of the particular mixture in the tank,” Viviers says.
He points out that the customer benefits from having two readings at the same time as this provides better control by having more accuracy on both density and level, thereby avoiding the use of too much of the flocculant or whatever liquid the customer is adding. This can be applied to any type of mixture where the density changes.
The third popular working model displayed at Electra Mining demonstrated the VEGA nucleonic detectors in action, in particular the MINITRAC density detector and the FIBERTRAC flexible detector. In the mining industry, the MINITRAC is used extensively for slurry density measurement. The FIBERTRAC is a nuclear level detector more for chemical and petrochemical industries and is used wherever a radar or other type of level measurement device is restricted or unable to work, due to being non-intrusive in the application. Both are used on round vessels and vessels with conical outlets suitable for measurement of liquids, solids, slurries and suspensions.
Viviers warns about using the right type of transmitters for the right application. VEGA has robust radar level transmitters for high demand applications, for the food industry, pharmaceutical, building materials, chemical industry, and mining, to name a few. “The production process is expensive and if a basic device fails, the consequence could be the loss of a batch of product,” he says.
VEGA pressure transmitters also cater for high and low demand applications. There are two main categories of pressure measurement: process pressure which could be any kind of pressure that exists in a plant, such as in a tank or pipe, and a gas pressure of some sort; and hydrostatic pressure which is using pressure to measure level applications.
A particular feature of the VEGABAR 20 and 30 series pressure transmitters, that customers particularly enjoy, is that operators can easily see what the pressure status is by looking at the colour of the LED ring which is configurable. Lower pressure shows green, high pressure shows yellow, and with extreme over pressure it shows red.
VEGA is well known in South Africa for not only its cutting-edge level measurement technology, but also has a wide range of pressure measuring devices for various applications. VEGA has a long history of innovation – over 60 years – and is recognised as a global leader in the field of measurement technology.
