Correct fluid levels ensure proper and safe operation in mobile working machines. The reliability and space-saving design of WIKA’s miniature magnetic float switches mean they can be used for almost all applications where fluid levels need to be monitored, from fertilizer tanks to engine coolant reservoirs. In addition, WIKA partners with customers to offer personalized solutions for level measurement.
WIKA’s horizontal miniature magnetic float switch is simple, compact, and very effective for monitoring fluid levels and as an indicator of maximum/minimum fluid levels in mobile machines. Just 98.5 mm to 134.5 mm (3.9 to 5.3 inches) in length, this device is ideal for applications where access to the top of the tank or available space is limited. It is particularly well suited for applications such as engine coolant units, hydraulic reservoirs, and agricultural chemical tanks.
How Does a Magnetic Float Switch Work?
The float of an HLS-M magnetic float switch is mounted on a hinged lever and travels with the level of the liquid. A built-in permanent magnet triggers a reed switch when the switch point is reached.
Magnetic float switches are one of the most reliable, low-maintenance tools for level monitoring. In this type of level instrumentation, a float – attached to a supported, swiveling lever – rests on the fluid’s surface. A permanent magnet is integrated into the lever, which moves up or down as the fluid level rises or falls. When the magnet in the lever reaches a pre-determined point, it actuates a magnetic reed contact that, in turn, closes (the standard operation) or opens a circuit – thereby triggering an alarm or another signal.
Since the switching function relies on the interaction between two permanent magnets, the operation is contact-free, meaning there’s no wear and tear. Furthermore, the switching function does not need a power supply.
Magnetic float switches work best when the media is not overly contaminated, does not have coarse particulates, and does not tend to crystallize. Any of these conditions can result in buildup on the float, which will hinder its movement and, therefore, impair the accuracy of the switch.
Advantages of WIKA’s Magnetic Float Switch
Designed to be mounted horizontally, WIKA’s HLS-M miniature magnetic float switches are compact and cost-effective tools for monitoring fluid levels in mobile working machines. The float itself is only 25 mm (1 inch) long in the plastic versions and 47 mm (1.85 inches) in the stainless-steel versions, making the HLS-M series ideal for small tanks, reservoirs, and any other vessels where space is an issue. As indicators of minimum and maximum fluid levels in tanks, the magnetic float switches are routinely used as dry-run and overflow protection.
The HLS-M comes in different materials to suit media type and conditions. The two models of plastic (polypropylene) switches work well between −10°C and 80°C (14°F to 176°F) and can withstand up to 1 bar of pressure, while the three stainless-steel versions are designed for temperatures between −40°C and 120°C (−40°F to 248°F) and pressure up to 5 bar. All five have ingress protection IP65 and are certified ISO 9001 and ISO 14001.
To make installation easier, the two models can be installed from the inside, and three from the outside. To optimize operations, you can choose from a variety of electrical and process connections. Custom cable assemblies are also available. The switching function is set for a rising level, and in standard use the contact is open. However, the switch can be configured as normally closed simply by rotating it 180 degrees. Thanks to its simple design and quality materials, there are minimal costs associated with mounting, commissioning, operating, and maintaining the HLS-M series.
Float switch model | Material | Installation | Electrical connection | Length (not including cable) |
HLS-M11 | Plastic (polypropylene) | From inside | Cable | 98.5mm / 3.88 in. |
HLS-M12 | Plastic (polypropylene) | From outside | Cable | 98.5mm / 3.88 in. |
HLS-M21 | Stainless steel 1.4301 | From inside | Cable | 97mm / 3.82 in. |
HLS-M22 | Stainless steel 1.4301 | From outside | Cable | 94mm / 3.7 in. |
HLS-M23 | Stainless steel 1.4301 | From outside | Connector | 134.5mm / 5.3 in. |
A reliable magnetic float switch with a small footprint, such as WIKA’s HLS-M series, can make a big difference in the operation, maintenance, and associated costs of your applications in mobile working machinery. Contact us today to learn more about these switches, their customizable options, and other innovative level measurement solutions from WIKA USA.
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