How does Guided Wave Radar (GWR) level measurement work?

Level  |  Monday, 6th February

Radar technology has been around and successfully deployed for industrial level measurements for years. But despite this, the concept is still viewed as relatively new by some. It means that some companies are missing out on the clear advantages that guided wave radar could offer their operations.


In spite of the advantages, the uptake of radar has been limited when compared to alternative tech, partly due to the perception that the method is still developing. ABLE Instruments’ product manager for guided wave radar (GWR), Gary Usher, explains that the fundamentals of guided wave radar level measurement come directly from time domain reflectometry (TDR).

TDR technology has been deployed for decades in a variety of situations, including being used to find breaks in underground cables or in-wall cable installations. The wide range of applications that TDR, and in turn guided wave radar, tech can be used for means it’s an option worth considering for many operators. TDR instruments work by emitting low amplitude, high frequency pulses. When launched into a transmission line, cable, or waveguide, it allows users to develop an understanding through the reflected signal amplitudes.

In GWR level measurement systems this technology is developed further and the waveguide probe can be used in liquid or dry, bulk media. Through transmitting high frequency electromagnetic pulses, guided wave radar is able to measure reflections and establish an accurate level of measurement. The dielectric constant for typical process media can range from 1.4–100, with the higher the figure, the stronger the signal.

Case study: ABLE – Always On The Radar


Recently, ABLE Instruments & Controls has worked with a major oil company to supply multiple radar gauges for a new project. The project had diverse requirements and challenges that meant we had to use our knowledge of manufacturers strengths and how best to apply different products to create a solution.

The oil company was building a new gas booster station in west Kuwait, a country well known for its oil exports in the Persian Gulf region. The firm’s plans were to build a new gas booster station that would be fed from existing and new gathering centres with the capacity to produce 234 million cubic foot per day of dry gas and 69,000 barrels per day of condensate. This would be achieved by a station that comprised of three high and low-pressure gas trains and thus reducing downtime and ensuring reliability were key.

The new development was part of the oil company’s aims to ensure that its able to meet both crude production and nominal gas export targets from its west Kuwait facilities. With the new gas booster station, the firm will be able to keep its output and production at sustainable levels while keeping flaring below 1%. The company that was contracted to build the new station selected us to supply multiple radar gauges, giving them access to our application knowledge and experience.

The scope of supply called for two different products, including 82 air firing radar gauges. We chose the VEGAPULS 61 to meet their needs. Thanks to the product’s minimal maintenance requirements, the company will be able to operate on a high plant availability without having to compromise on results that give exact measurements, independent of process conditions. We also provided eight GWR’s, selecting the VEGAFLEX 81. They incorporate many of the key selling points of the air firing radar gauges, with comprehensive diagnostic possibilities to ensure a maintenance-free operation and high plant availability. With the facility to shorten probes they also offer flexibility in the planning phase. The GWR’s were also safety integrity level 2 (SIL2) certified.

The customer’s special material requirements needed to be compatible with the high media temperatures and the sour service common to the processes in the new station. What’s more, the majority of the non-contact radar needed to be removable without shutdown. We resolved this problem with stilling wells and spool pieces, so that gauges could be easily and quickly isolated via a supplied valve. The solution gives the operator more flexibility. Some components also had to be supplied with flange insulating gasket kits to negate the risk of dissimilar metal corrosion.

We were also able to provide further assurances against surface and subsurface discontinuities through stringent testing, involving dye penetrant inspection, positive material identification, X-radiography and magnetic particle inspection. The responsibility for performance verification of the radar gauges also fell on ABLE, and this was carried out on the level measurement test rig at the company’s UK facility.

As well as providing the radar gauges for the new gas booster station, we also covered a pipeline network from the gathering centre units to the booster station and an intermediate slug catcher.

247able – VEGA Instruments

If you’re interested in using VEGA Controls’ instruments within your operations, our e-commerce division, 247able, is a leading UK based distributor, stockist, and service provider for a range of products.

VEGA Controls, also known as VEGA Instruments and VEGA Grieshaber KG, have an outstanding reputation across the globe for providing excellent level and pressure instrumentation for the process industries and we can help meet your needs. Our comprehensive VEGA Controls portfolio includes many of the brand’s distinguished products and ranges, including VEGABAR, VEGAFLEX, VEGAPLUS, VEGASON, VEGASWING, VEGAVIB, and VEGAWAVE. Where necessary we can also provide products that are SIL2 and meet EU ATEX directives for equipment in explosive atmospheres.

VEGA Controls offers industry proven air firing technology and guided wave radar that can be purchased from 247able. Companies can cover all their continuous and point level requirements from the range of available VEGA technologies, including ultrasonic and capacitive sensors, conductive and vibrating switches, which can be utilised for both solid and liquid media. We understand that sometimes you need your order quickly and can deliver all our stocked VEGA Instruments products the next day if ordered before 16:00.

ABLE Instruments & Controls – Solution Provider

ABLE know how important every piece of equipment can be in an industrial setting, not only to ensure that operations continue safely throughout the day but to meet specific business demands and requirements.

We’re a leading global company recognised for providing services and products that meet a variety of demands. Whether you want equipment that will minimise operational disruptions or maintenance, saving you both money and time and increasing output, we can support you in finding a solution. We take the time to work with our customers to understand exactly what it is they need and then use our industry insight to make recommendations.

If you’re interested in ABLE Instruments & Controls products, services, or expertise, you can contact us now at [email protected] or via phone on +44 (0)118 916 9420.

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