Product Portfolio
AMS Technologies’ portfolio of liquid level sensors and switches is designed to manage liquid levels of water, foodstuffs, chemicals and fuels in all sorts of containers and vessels. Standard solutions available from stock include vertical float switches, both in single and multiple level versions. These float switches utilize reed switches in a stem that are activated by a magnet in a float.
Beyond the float switches available from stock, AMS Technologies offers a broad range of general purpose vertical float switches, available in a variety of materials for stem and float, with a choice of gasket materials, to suit most commonly used liquids. Special versions allow detection of very low levels of liquid or variable insertion depth that can be additionally extended by dedicated extension tubes. In addition to single switch point sensors, a series with 4-20 mA analog output is available, providing a continuous signal over the full measuring span.
Vertical float switches manufactured from stainless steel can be used in aggressive liquids or hygienic applications. These sensors are available from AMS Technologies with short or long float travel, with single or dual switch point and also for high temperatures up to +200 °C or higher pressures up to 40 bar.
General purpose horizontal float sensors available in a variety of materials allow fitting from the inside or the outside of the tank. Special versions feature a tapered mounting thread, an integrated temperature sensor or a float pivot above the liquid surface, also available with a wider differential between the opening and closing levels.
Stainless steel horizontal float sensors, ideal for use in aggressive liquids, hygienic or food-grade applications, are also available for internal or external fitting. Miniature versions are suitable for applications with restricted space, and switches with a tapered thread allow short fitting times.
Our range of cable end float switches is designed to be suspended into the liquid by its cable. Within this range, float switches for indoor or covered tanks are available as well as devices for use in exposed tanks or turbulent liquids, also available with a compact design for confined spaces and even suitable for level indication in narrow boreholes.
You can’t find the float switch in our standard range that fully meets your requirements? Get in touch with AMS Technologies to discuss your custom engineered variant. Our suppliers have a solid history of customizing float switches for a wide range of industry sectors including oil, gas and petrochemicals; food and beverage; chemicals and pharmaceuticals; water and wastewater or process manufacturing – and for any type of environment including industrial process control, safe areas, intrinsically safe and hazardous areas (ATEX-certified) as well as WRAS-approved switches for drinking water applications.
Related Products
In addition to liquid level sensors, AMS Technologies carries a broad range of further sensor solutions.
Our portfolio of flow sensors is used to measure flow rates and often also the total volume of liquids flowing through a specified cross-section. With inline, paddle and ultrasonic flow sensors or switches, AMS Technologies provides solutions for a large number of applications.
A broad range of pressure sensors is available from AMS Technologies, comprising models for gauge and absolute pressure sensing with variants for low pressure ranges as well as pressures of up to 400 bar. Featuring piezo-resistive ceramic technology and a microprocessor-based amplifier, these pressure sensors in a stainless-steel housing provide excellent media compatibility and are suitable for a wide range of industrial applications
AMS Technologies’ accurate and fast temperature sensors are essential for precision temperature control. Our extensive range of NTC thermistor probes provides very high sensitivity, small size and appropriate speed – perfect for use with our temperature controllers. Thermopile sensors, detectors, modules and arrays available from AMS Technologies offer leading-edge, non-contact temperature measurement for various applications – with some models additionally allowing for motion detection and presence monitoring.
Our product range of current sensors includes super high performance, lab-grade current transformers allowing non-contact measurement of currents from Microamperes to 20 Kiloamperes, at frequencies ranging from 0.5 Hz to 500 MHz.
Definition
In many industrial processes, the level of liquids stored in different containers such as tanks or chambers has to be measured. For this purpose, liquid level sensors provide signals that are used to control the production process or for status indication. A magnetic float combined with a reed switch is one of the most reliable and proven technologies for level measurement. This relatively simple design is reliable in the long run without the user having to calibrate the float switch. When selecting a float switch for a liquid level sensing application, several factors such as the materials of float switch and gasket, physical arrangement, electrical performance and cable type must be considered.
Physical Arrangement
Which sensor design is suitable for your application? The answer depends on the physical arrangement of the tank and the possible installation positions as well as on whether the inside of the tank is accessible or not. While the horizontal or side mounting type normally has a fixed housing mounted in a hole in the side wall of a tank and a hinged float attached to the fixed housing, the vertical mounting version (installed through a hole in the top or bottom of a tank) usually features a fixed vertical shaft, along which slides a cylindrical float.
Any possible liquid deposits on the float body must also be taken into account. Accumulations of these deposits over time may cause the float switch to fail. Specially designed float switch types can minimize the effects of this build-up - to find out more please contact us with your requirements.
Material Selection
Choosing the right material for a float switch is very important. If materials are chosen that are not compatible with the liquids and temperatures of the application, parts of the liquid level sensor can be damaged and ultimately the float switch can even fail completely. Depending on the process fluids present in the application, tests with a sample switch may be necessary to ensure compatibility.
Some typical materials for liquid level sensors are nylon (suitable for many oils, diesel, organic chemicals and MEK-based inks), polypropylene (PP, many acids and alkalis, detergents, inorganic and organic chemicals, oils and water), polyphenylene sulfide (PPS, many of the more aggressive chemicals and process temperatures up to +120°C), Buna/Nitrophyl (many oils, diesel, petrol and water in non-potable applications), D300 foam (PVC, most hydraulic oils and many chemical solutions) and stainless steel (most medical and food applications, chemicals, hydraulic fluids, fuel oils and process temperatures up to +135°C).
Electrical Ratings
To ensure reliable operation, it is important to fully understand the type of load to be switched and to ensure that the float switch can handle that load. In most cases, the electrical ratings provided in the float switch specifications refer to purely resistive loads - however, if loads with inductive or capacitive components are to be switched, appropriate measures must be taken to protect the contacts against wear and destruction.
Cables
Whenever aggressive liquids may spill onto external wiring, particular materials have to be specified for the float switch connection cables – from standard, UL-approved cable types all the way to high-temperature, low-smoke zero-halogen (LSZH) and other specialised materials.
Alternative Terms: Liquid Level Switch; Level Sensor; Level Switch; Liquid Sensor
