The VEGAFLEX 80 Guided wave radar level transmitter, was originally assessed for SIL conformity when independently judged and certified by TÜV Rheinland according to IEC 61508:2010 (Ed.2). It is also now the first Guided Wave Radar level sensor to also be independently assessed by engineers from EDF Energy Nuclear Generation Ltd, as part of the EMPHASIS project to satisfy requirements on EDF as a Licensee under the auspices of the Office of Nuclear Regulation (ONR). It is now deemed acceptable for this sensor to be deployed in suitable SIL2 applications for the UK Nuclear industry.
The Control & Instrumentation Nuclear Industry Forum (CINIF) developed the EMPHASIS program after extensive research. Although it originally began as a set of written guidelines, the EMPHASIS program soon evolved into a software tool that can be used for assessment of SMART instruments suitability for the nuclear industry. Extensive validation has been applied to EMPHASIS, and has been adopted by the Nuclear Industry Smart Instruments Working Group (NISIWG) which comprises of the major players in the UK nuclear sector. As VEGAFLEX GWR level transmitters are SMART instruments, it is imperative that the verification of these products meet EMPHASIS nuclear requirements. EMPHASIS is based upon a lifecycle approach as specified in IEC61508. This provides an evidence gathering tool in the form of a comprehensive set of questions covering all relevant aspects relating to both the product and manufacturer under review.
VEGAFLEX GWR’s measure level by guiding a microwave pulse to the surface that needs to be measured. In this type of radar level measurement, microwave pulses are conducted along a cable or rod probe which extends over the measuring range required and reflected back by the product surface. The measuring probe of the GWR sensor ensures that the signal is guided to and from the product surface undisturbed. Liquids, liquid gases, solids and interfaces in liquids are commonly measured with this measuring technique. Microwaves are used as they are virtually unaffected by temperature, pressure, vacuum and vapour in the airspace above a product. They are also unaffected by changes in density or conductivity of the product and with no moving parts, there is no drift or recalibration required. This versatility means a GWR can be employed in a wide variety of level measurement and control applications. They are capable of measuring ranges up to 60m and they can be used for level control in tanks, vessels, silos, ponds and sumps, across many process and storage applications in the nuclear power generation sectors. A GWR can also be mounted in bridles and bypass chambers for use in steam drums, or applications where a stilling tube arrangement is desirable. VEGAFLEX is easy to set up, with a wizard guiding the user step by step, either with the head mounted plug in PLICSCOM programmer, or via PC with free to download universal PACTware software. VEGAFLEX joins the VEGAPULS non-contact radar transmitter as the second level instrument from VEGA to be successfully EMPHASIS assessed.