Adaptable MultiMulti-Point Fluid Level Sensor REED RELAYS REED SENSORS REED SWITCHES Introduction Liquid systems all have their own specialty aspects and their own peculiarities. The liquids vary in density and viscosity (flow level) in going from water with a centi-poise of 1 to liquid epoxies having up to 10,000 centipoise. Also, the temperatures can vary from -40°C for flour-inert (3-M liquids) to 200°C for pressure heated water and other special liquids. Meeting these extremes is no easy matter. MEDER’s new LS04 series attacks these extremes along with multiple sensing points and multiple floats. Therefore, liquid baths having two or more different liquids with different densities and viscosities can be simultaneously measured and their liquid levels monitored. Figure 1. A triple float sensor connected to the top part of a container Features • All inclusive fluid level sensor having the sensing element (reed switch), float, and magnet all as one component mounted on a PCB internal to the stem • Ability to perform under hot and cold liquid systems • Up to 9 point liquid level sensing • Up to 6 active floats on one stem or shaft • Meets RoHS Directive 2002/95/EC • Hermetically sealed • Dynamically tested contacts • Reliable switching • Stem length for 100 mm to 250 mm • Ability to exist in oil, gasoline, petrol, water and mild acids Applications • Single and multipoint liquid level sensing for an assortment of liquid systems running either hot and/or cold fluids Figure 2. A representation of the versatility of the LS04 series showing multiple float and stem configurations. MEDER’s Versatile Approach to Liquid Level Sensing Offers the Needed Design Answers Because of the plethora of requirements in liquid systems, sensing the levels and controlling their depth, takes on an assortment of requirements. Essentially every liquid system needs liquid level controls and almost all require a unique set of sensing parameters. For one sensing company to tool all these level sensing conditions would be insurmountable. MEDER’s goal however, is to satisfy all our customer’s requirements. To solve this conundrum the MEDER engineers have cleverly developed a set of tools that offer the versatility needed to satisfy the above requirements. The LS04 Series approach has been tooled to handle up to 9 sensing positions and up to 6 individual floats on one shaft. This tooling versatility allows us to meet most of the more challenging Liquid System level sensing requirements. The stem or shaft ranges from 100 mm up to 250 mm representing a long vertical sensing range. Standard PVC cable is used to protect and insulate the electrical wiring that is all epoxied into the stem. This tooling can be molded in various plastics, each capable of meeting the rigors of certain liquids. For instance molding the stem or shaft of the sensor with polyamide (PA) and a float of NBR (Nitrile Butadiene Rubber) will allow usage in oils, gasoline, and petrol. Using Polypropylene (PP) will be ideal for water and dilute acidic liquids. MEDER electronic Application MEDER electronic AG | Germany | tel.: +49(0)7731/8399-0 | Email: [email protected] MEDER electronic Inc. | USA | tel.: +1 508.295.0771 | Email: [email protected] Page 1 of 2 www.meder.com Adaptable MultiMulti-Point Fluid Level Sensor REED RELAYS REED SENSORS REED SWITCHES Specifications (@ 20° 20°C) LS04 Series Operate specs Min Max Units Must close distance Ref Ref mm Must open distance Ref Ref mm Min Max Units Hysteresis Load Characteristics Switching voltage Switching current Carry current Contact rating Static Contact resistance Dynamic contact resistance Breakdown voltage Operate time Release time Operate Temp Storage Temp 1000 1.0 2.0 100 150 200 4000 -40 -20 0.8 0.05 200 100 V Amps Amps Watts mΩ mΩ V msec msec °C °C MEDER’s new designs encompass it all – the reed sensor, the float, and the magnet along with a PCB and its associated circuitry. This saves the system designers valuable time by only having to specify and qualify one component. They no longer have to work with several different suppliers and coordinate between them. Since this sensor requires some electrical circuitry, using a printed circuit board with plated thru solder holes guarantees reliable connections using an automated wave soldering system. The PCB is a long thin circuit board that runs down the length of the stem. And in this manner the hermetically sealed reed switches are properly placed and positioned In their sensing locations. Another critical element is the acknowledgement that during assembly, problems can occur. MEDER tests all sensors 100% for all operating conditions, but in addition tests for dynamic contact resistance (DCR). Essentially this test is a guard against the many faults that can occur during assembly. If the reed contacts have any internal contaminations; or the reed capsule has been stressed or a slight crack has occurred, this DCR will detect these conditions and reject the sensor. This testing is all carried out in an automated testing system. MEDER’s design for manufacturing approach provides a long reliable life in the field. Consult our engineering group with your specific applications. Adaptable Liquid Level Series Series LS04 LS05 Dimensions mm Illustration inches W 25 0.984 H 25 0.984 L 165 6.496 0.2760.630 0.2760.630 3.15078.740 W H L 7-16 7-16 802000 Liquid Level Series Series LS01 LS02 LS03 Dimensions mm W 19 H 24 L 42 W 19 H 24 L 75 W 25 Illustration inches 0.748 0.945 1.654 0.748 0.945 2.953 0.984 H 25 0.984 L 80 3.150 **Consult the factory for more options not listed above. ** MEDER electronic Application MEDER electronic AG | Germany | tel.: +49(0)7731/8399-0 | Email: [email protected] MEDER electronic Inc. | USA | tel.: +1 508.295.0771 | Email: [email protected] Page 2 of 2 www.meder.com