Homepage » Instrumentation & Automation »

Functional safety for level measurement with 80 GHz

Using radar technology in SIL applications
Functional safety for level measurement with 80 GHz

Focused 80 GHz signal radiation unequivocally offers new options for level measurement in small, narrow or very tall tanks and silos with complex geometries. Even fittings inside tanks no longer have any influence on the measuring signal. To minimise the effort and risks involved in SIL applications, a free-space radar measuring device had to be developed directly in accordance with IEC 61508. Nevertheless, high frequency is not the be-all and end-all.

There is no doubt as to why functional safety is so important: every year, around 313 million people have accidents at work requiring short or long-term medical intervention. Plant operators are investing heavily in ways to eliminate these on-site dangers to people. Ultimately, every preventative measure is far cheaper than an accident, not to mention all the associated consequences for the people involved as well as for the process, the plant and the environment. In these circumstances, the costs can easily amount to ten or twenty times the figure for actually building the plant. In spite of this, an investment in functional safety and, by extension, measures to prevent accidental or systematic errors remains very straightforward, provided you rely on measuring instruments that have been developed strictly in accordance with IEC 61508. This standard affords increased safety for plant operators, reduces the length of the “proven-in-use” phase and shifts a significant share of the burden for the necessary measures and documentation onto the manufacturer.

Manufacturer safety
IEC 61508, the international standard on the functional safety of safety-related electronic systems, makes certain demands on the manufacturers of measuring devices. They need to have a comprehensive quality management system that focuses on safety aspects, otherwise known as functional safety management. Both the hardware and software must be designed so that they prevent systematic errors, while the hardware additionally requires an accidental error monitor and a quantitative calculation of the failure probability. The devices must of course also meet the requirements for the planned operating environment in terms of temperature and other parameters while the provision of clear, simple user documentation – including a product safety manual – is absolutely essential. Measurement technology customers invest in safety and documentation in order to ensure transparent and traceable product manufacturing processes.
The benefits of 80 GHz technology
Endress+Hauser’s presentation of the Micropilot NMR81 for custody transfer at the beginning of 2016 heralded the first high-precision 80 GHz radar for liquids. The company is now also launching the free-space radar with 80 GHz technology in the market for standard applications. The gas-tight feed-throughs in the housing and the self-monitoring and diagnostics using Heartbeat Technology instantly increase the safety of the plant. Heartbeat Technology provides the option of verifying the measuring device on site or of running repeated tests in accordance with SIL or WHG (German Water Resources Act) – automatic documentation included. In addition, Heartbeat Technology yields more knowledge about the process and sensor status for monitoring, so that any foam or build-up, for example, is detected and unscheduled plant downtime prevented.
The benefits of small, focused 80 GHz signal radiation are obvious. It reduces the influence of the tank walls and the measurement itself is considerably less susceptible to restrictions caused by obstacles and fittings in the tank. The device can be installed in long tank nozzles without an antenna extension or alternatively using a ball valve. Since fittings and tank walls have no effect, the Micropilot FMR6x also measures reliably at a distance of up to 125 m, though it can still be installed in small tanks thanks to its compact process connections.
The 80 GHz frequency additionally has benefits during the measurement itself because it enables longer measuring ranges as well as measurements of media with low dielectric constants, for example, as less energy is lost on obstacles. The new technology opens up novel fields of application in tanks or silos with complex geometries, fittings and long nozzles. Finally, a clutter suppression system makes the commissioning process much simpler.
Endress+Hauser has put a great deal of time and money into designing the new Micropilot FMR6x with 80 GHz technology, in order to ensure strict conformity with IEC 61508. This TÜV-certified development process prevents the occurrence of systematic errors and the measuring devices can be used in both SIL2 and SIL3 applications with homogeneous redundancy.
The sum of all radar frequencies
Despite the numerous benefits of this technology, it is important not to lose sight of the alternatives to 80 GHz. High-frequency radar undoubtedly opens up additional opportunities but it does not solve all the challenges of the many different applications. Sometimes, measuring devices with 1, 6 or 26 GHz – or with a different measuring principle entirely – are more suitable. The experts at Endress+ Hauser have therefore cleverly expanded their range so that the sum of all its parts adds up to 113 GHz, keeping the frequency range visible to everyone. In the end, only useful, efficient solutions that meet the requirements will prevail.
Every frequency has its own advantages, which is why measuring with 1 GHz on the guided radar is preferable for processes involving foam generation or very low dielectric constants as well as for gas phase compensation or for interface and bypass measurements. The strengths of the 6 GHz radar are most evident at high levels of condensation, making it ideal for surge pipe or duct applications. The “all-rounder” measures with 26 GHz and is suitable for around 90 % of all applications, including turbulences. The high-frequency 80 GHz radar stands out with its narrow emitting angle, measuring range of up to 125 m and optional maximum precision up to 0.5 mm.
Hall 11, Booth C43
www.cpp-net.com search: cpp0217endress

Integration in the two-wire device concept

Uniformity

In the process industry, the requirements for automation engineering are constantly rising. Ever more powerful and more flexible systems covering the entire range of measuring applications have to be operated at the lowest possible cost. The complexity for users is continuously mounting due to the wide variety of measuring tasks and the devices available for them from various vendors. Simultaneously, the specifications with respect to plant operational safety, reliability and availability are increasing.
Endress+Hauser implements these requirements by fully integrating the new versions of its Micropilot FMR6x free-space radar into the two-wire concept for flow rate and fill level.
This uniformity is visible, for example, in the documentation, operation, diagnostics, Ex and spare parts concepts as well as in numerous other details, leading to a reduction in the costs for planning, purchasing and operation.

Carsten Schulz
Marketing Manager Level,
Endress+Hauser Messtechnik
All Whitepaper

All whitepapers of our industry pages

Current Whitepaper

New filtration technology for highly corrosive media


Industrie.de Infoservice
Vielen Dank für Ihre Bestellung!
Sie erhalten in Kürze eine Bestätigung per E-Mail.
Von Ihnen ausgesucht:
Weitere Informationen gewünscht?
Einfach neue Dokumente auswählen
und zuletzt Adresse eingeben.
Wie funktioniert der Industrie.de Infoservice?
Zur Hilfeseite »
Ihre Adresse:














Die Konradin Verlag Robert Kohlhammer GmbH erhebt, verarbeitet und nutzt die Daten, die der Nutzer bei der Registrierung zum Industrie.de Infoservice freiwillig zur Verfügung stellt, zum Zwecke der Erfüllung dieses Nutzungsverhältnisses. Der Nutzer erhält damit Zugang zu den Dokumenten des Industrie.de Infoservice.
AGB
datenschutz-online@konradin.de