Electricity and Control March 2024

COVER ARTICLE

Radiometry – the best measurement technology when others fail

H igh temperatures and pressures, aggressive atmos pheres, phase formation, changing gas densities, build-up on vessel walls – extreme process conditions are not unusual in many industries. Processes that take place under such conditions must be monitored reliably. Mon itoring is not only important for safety reasons, but also supports process optimisation. Measurements of density, level or level switch play a key role in ensuring that critical processes are safer. If you compare the available meas urement technologies, you will inevitably come across ra diometry in the face of extreme measurement conditions. For more than 75 years Berthold has been providing such systems, installed in thousands of applications, and proven under the most demanding conditions. The principle of attenuation Typically, a radiometric measurement system consists of two components: a source that emits gamma radiation and a detector that can detect the incident radiation. In most cases, these two components are positioned on the opposite sides of the geometry to be measured, such as a vessel or a pipeline. The measuring principle is based on a simple but ingenious concept – the principle of attenuation. The gamma radiation passes through the vessel, as well as its contents, and is then detected by the opposite detector. Depending on the amount and density of the material to be penetrated, the radiation is attenuated to a greater or lesser extent – more material and higher density lead to more absorption. The radiation arriving at the detector is thus a measure of the attenuation and, with the use of appropriate calibration, the relevant measured value, such as density or level, can be determined. Individuality thanks to a broad portfolio To be able to meet a wide variety of measurement geometries and requirements, there is no single, universal radiometric solution. Only through a combination of different sources and detectors is it possible to find the perfect, customised solution for each measurement task. Advantages of contactless technology As noted above, radiometry is implemented widely in extreme process conditions. One of the reasons for this

is the noncontact technology, whereby the measuring components themselves have no contact with the material being measured. Due to the external mounting, installation is remarkably simple and measuring equipment can easily be retrofitted to existing vessels or pipelines.

One of the biggest advantages of radiometry is that it is maintenance-free and does not require recalibration. The operating costs are therefore low compared to other technologies. Other characteristic properties of this technology are its temperature and long-term stability. Most users have been applying radiometric measurements for many years without any performance problems. Mecosa (Pty) Ltd is the sole business partner for Berthold in Southern Africa and has cooperated with Berthold for more than 35 years. □

Typical setup of a radiometric measurement.

For more information contact Mecosa. Tel: +27 (0)11 257 6100 Email: measure@mecosa.co.za Visit: www.mecosa.co.za

MARCH 2024 Electricity + Control

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