An easily visible level indication was one of several features taken into account in the development of the FlexLevel Switch at the request of customers. Now, a bright blue light shines on top of the switch, which can be seen even if the sensor is mounted on top of a tank. The adjustable sensor length, various certifications like Atex and 3A, a teach-in function, flexible output signals and the opportunity to zoom in on a specific medium were also incorporated in response to customer needs.
Point level detection is one of the most common applications in the process industry for avoiding overflow or dry running. Application-specific factors like foaming, highly aggressive or inflammable substances as well as very harsh environments have to be considered. Furthermore, the highest hygienic standards have to be met, especially in the pharmaceutical, food and beverage sectors.
The Baumer FlexLevel Switch is a versatile level measurement device that can easily be configured on a PC. Instead of the LED indication used in the past, a bright blue light on top of the switch now shows that a medium has been detected. Even if the sensor is mounted on top of a tank, this indication can be recognised without difficulty. The level switch was developed for hygienic applications, which is why all wetted parts are made of FDA-approved, acid-proof stainless steel or PEEK thermoplastic. The level switch complies with EHEDG requirements and has 3A approv-al. For applications in hazardous areas (zones 0, 1 and 2), it can also be supplied in an Atex version.
The FlexLevel Switch detects the level of liquids, viscous fluids and even dry media. For particularly problematic media like adhesive substances, the teach-in function supports manual adjustment of the level to be detected. The switch is also suitable for pharmaceutical applications, such as detecting the level of ultra-pure water. Foaming, bubbling or lumping does not limit its functionality, and nor do vibrations or vorticity. Since the mounting position has no effect on performance, the sensor can be installed laterally or at the bottom of a pipe, for instance to protect against dry running.
In the standard version, the FlexLevel Switch is designed for permanent process temperatures from -40 to +85 °C. However, it is also suitable for use in CIP and SIP facilities in which peak temperatures as high as 140 °C can occur (max. 1 h). In conjunction with the optional 100 or 250 mm cooling neck, the switch can even be used at process temperatures up to 180 °C. The cooling neck features a sliding connector and can therefore serve as an extension, e. g. if the sensor tip has to reach deeper into the tank with viscous media like yoghurt or the media has to be accessed through the tank insulation. When used in open or closed tanks, the device can withstand pressures up to 16 bar. Since the FlexLevel Switch does not contain any moving parts and its electronic unit is completely integrated, it is practically maintenance-free, allowing precise limit detection without having to adjust the switch point.
Foaming processes
The FlexLevel Switch sends out electro- magnetic waves, which undergo a propagation delay owing to the medium and are subsequently returned to the evaluation unit via the metal tank wall or welded socket. When the medium reaches the sensor tip, the delay of the electromagnetic waves that are emitted changes according to the medium’s dielectric value. All media with a minimum dielectric constant of 1.5 can be measured. As a result, the level switch is ideally suited for foaming processes. Since macro to fine-pored foam has a lower density than the fluid itself, it is often not recognised as detectable liquid. The switching function – whether normally open or normally closed – can be realised by altering the type of connection. The chief benefit of this measuring technology lies in the small conical socket extending into the medium. Whereas with other methods, the device requires a larger surface to which pasty or adhesive media can easily adhere – a frequent cause of malfunctions – the media is unlikely to stick to this tiny adapter. A special 3A welded socket ensures hygienic integration into the process and offers the advantage of a lateral bore hole that reveals any leakage due to abrasion of process fluids.
The FlexLevel Switch can be connected to a PC and is configurable with FlexProgrammer 9701, simplifying fine adjustments and allowing the user to hide or zoom in on a particular medium, for example in order to separate it from a CIP cleaning preparation. Alternatively, all set-ups can be entered directly on the level switch. The configuration tool can also be used for online measuring and data logging as well as for manual adjustments of the switch trigger and hysteresis points.
Hall 9, Booth G06
Online-Info www.cpp-net.com/2110433
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