Fluid Switch Blog

Category Archives: General

What is a Vertical Float Switch?


A vertical float switch is a mechanical device that monitors liquid levels inside a reservoir tank. Regardless of the application, vertical float switches have one main purpose: to trigger an event when the liquid reaches a certain level.

What kinds of events can vertical float switches trigger? Refills, ceasefires, and discharges. Consider a typical dishwasher for example. Most modern dishwashers use vertical float switches as a backup for the fill timer. In the event that the timer fails to work properly, the float switch shuts the water off so that the dishwasher does not overflow.

How Vertical Float Switches Work

Vertical float switches are made up of two main components: a center tubed magnetic float and a reed switch. Both the float and the reed are operated by magnets. When the float reaches a predetermined level, the reed switch reacts by closing or opening.

In the dishwasher scenario, the float rises as the water fills; once the float reaches a certain level, it triggers the reed switch, and the process ends: the reed switch sends a signal to open or close (depending on how it’s configured by the manufacturer), and with that, water ceases to fill the dishwasher.

Common Applications

Due to their versatility and trustworthy design, vertical float switches are used by many different industries for a variety of different applications, like:

  • Boilers

    Like dishwashers, boilers require safety measures to work properly. If nothing existed inside the boiler to monitor and stop high water levels, then houses all over the country would flood. This is where vertical float switches come into play. The vertical float switch can trigger alarms that regulate pump controls, prevent overflow, and shut the system off entirely if extremely low water levels are reached.

  • Fish Tanks

    Water in fish tanks evaporate over time, and when water evaporates, salt is left behind. Unfortunately, even saltwater fish can only handle so much salt. Since fish can die from an excess of salinity in the water, fish tanks are often built with a top-off system that pumps freshwater in if salinity levels are heightened. Top-off systems use vertical float switches to automate the pump: when a risky amount of evaporation occurs, the reed switch closes, and the pump activates. Freshwater then gets pumped into the sump until the float switch opens. When this happens, the pump deactivates.

  • Water Wells

    Many water wells use vertical float switches to activate and deactivate well pumps. Two float switches are often used: one near the top of the tank, and one toward the bottom. The switch at the top cuts the electrical connection to the pump if the water level gets too high; the switch at the bottom connects to the pump if the water level gets too low. These two switches work simultaneously to keep the tank filled at an optimal level.

SMD Has The Right Vertical Float Switch For You

If you’re curious as to how a vertical float switch can meet your unique needs, then SMD has you covered. Not only do we manufacture a variety of different float switches, but we know these devices inside and out. We can also create custom applications based on your specific application needs. Don’t hesitate to contact us today. We will help you select the float switch that’s right for you.


Partnering with Design Engineers on Custom and Standard Builds

engineer partnership

The job of a design engineer is unique and often cumbersome. Across industries, they must rely on physics, complex scientific and mathematical techniques and sometimes even create something that’s not been done before.  Along with this inventive requirement, they’re also responsible for safety, meeting compliance and other standards all while doing this within a budget constraint.

That’s a lot to take on. By working closely with the manufacturing engineer and a team of designers throughout the product lifecycle and leaning on other experts in the industry, there is much benefit to be had. Cost and time savings and a product that works exactly as you intended it to.

After having researched and specified the requirements of the project and finding that there is a need to sense a liquid within the parts, calling on the experts at SMD Fluid Switch as a partner makes sense.

Here’s why.

We Do Level Sensing

We’ve been designing custom sensors to measure force, pressure, temperature, weight, torque, liquid level and many combinations of these since 1978. As a manufacturer and supplier of a wide variety of fluid switches, float switches, temperature gauges, and liquid level sensors. We have the experience in design and the integration of sensors into custom designs and can create solutions that meet your specifications.

These include machined level sensors, optical switches, ultrasonic level measurement, and custom molded float switches in metals or plastics like stainless steel, polypropylene, and nitrile butadiene rubber (NBR).

We Keep it Cost Sensible

We work to lower costs and increase productivity for all of our clients, offering competitive pricing for OEM designs and applications.

So whether you’re an automotive engineer and looking to add a fuel sensor to a gas tank, or a design engineer designing a countertop beer brewing machine and in need of water level management sensors, we’re here to help!

We Serve a diverse range of industries, including Aircraft and Aerospace, Alternative Energy, Boiler, HVAC and Air Handlers, Breweries and Wineries, Chemical Processing, Food Processing, Industrial Equipment, Marine, Medical, Oil & Gas, Specialty Vehicles: ATV, Farm Equipment, Water and Wastewater, and Manufacturing.

Engineers: Don’t go it alone when you’re designing a build. Get in touch today!


Customized Sensors: Get the Fit You Need

Fluid sensors and level switches are used in a number of applications across industries to provide leak detection, overflow alarms, low-level warnings and even overfill shutoffs. In many of these cases, they are detrimental to operations and livelihood.

These sensors can be mounted on vessels in a number of different ways – top, side and back mounted, for example, depending on a number of factors. When used, they provide an accurate measure of the contents inside. Applications like agricultural machines, fuel delivery systems, chemical processing and so many others all make use of the sensors to operate safely and efficiently each day.

customized sensor

Sometimes though, basic won’t cut it. Standard sensors are great for so many reasons, yes. They help get the job done, offer protections and necessary advanced warnings -but what happens when you have a harsh environment, above normal heat requirements or serious dangers present?

At Fluidswitch we offer OEM customized versions of standard sensors so they can do what you need them to for your application.

Here are just some of the reasons why customizing sensors may be necessary:

  •           Safety Concerns

Depending on operating conditions and your specific application, you may require extra safety outside of the usual. In rugged applications or where discrete wiring and jackets on cables for volatile environments is necessary you may need a custom-designed sensor.  Our team will work with you to make sure your demands are met.

  •        Temperature Demands

For some applications, maintaining a certain temperature as well as liquid level in the vessel is critical. Think about bottling consumer beverages or chemical processing plants where accurate temperature maintenance will make or break an outcome. Fluidswitch can integrate both of these capabilities into a single unit to help you save space and resources while achieving the correct outcomes.

  •     Unique Batch Requirements

Another reason you may be wondering about customization for level sensors and float switches can relate to how large or small a job is. If you’ve taken on a load that’s not typical for your usual production numbers and you don’t want to over order unnecessary resources, no matter the quantity, SMD Fluid Controls will work with you no matter the quantity – large and small and get you the parts you need.

Have questions? Ask us about customizing parts to fit your needs!

Contact us today to schedule a consultation!


Level Sensors: How They Work & What They Do

liquid level sensors

How do you measure the level of liquid in a contained space that’s flowing freely and in some cases too hot or dangerous to come in contact with? The answer is –  Level Sensors.

Using a magnet and reed, the most basic sensors can monitor liquid levels through the activation of switches that activate alarm about too much or too little liquid present in the container.

But don’t let their simplicity fool you. Level sensors aren’t just loved because of their cost sensibility, they are also vital to operations in industries across the globe. They don’t just measure the presence of a medium in a container, but also the absence. These low-level warnings and can even detect leaks before dangerous situations occur. This accuracy and dependability keeps businesses successful and the public safe.

Liquid measurement and monitoring is so important in fact, that new devices and technologies continue to incorporate the sensors in them as a way to deliver important data to and from advanced machines.

Depending on the type of process materials being measured, different sensor types can be used.

Two options for how to handle materials are typically chosen from – contact or non-contact measurement. This is based on various factors from the density to the temperature of the material being measured and whether or not there are sanitary requirements. As the name indicates, a contact measurement method would be the sensor located inside the vessel itself and able to come in contact with the material being measured without putting the project at risk. A non-contact method would include a sensor mounted to the outside of the tank.

Here is a break down on the different types of sensors offered by SMD Fluid Controls.

Contact Sensors:

Float Switches – These are the most commonly used devices for level measurement and utilize magnetic floats and reed relays to measure liquid medium.


FL50 – Chemical Resistant Plastic Ultrasonic Point Level Sensor


Contacting UltrasonicThese options are great for point level measurement of liquid and work by measuring the timing and speed of sound waves.

Optical SwitchesThese sensors have built-in electronics and work with no moving parts. They can perform point level sensing and pressure sensing up to 2500 psi.

optical sensor

OS950 – Miniature Plastic Optical Level Sensor

Submersible Tank Level Sensor – These are a versatile option that can gauge tank levels by the hydrostatic pressure and offer stable and continuous measurement from depths up to 211 meters.

submersible sensor

FT60 – Downhole Submersible Level Sensors

Non-Contact Sensors:

Ultrasonic Radar – This option uses radio waves to measure levels and is best for highly viscous or difficult liquid media that must be measured in real-time. Our ultrasonic sensors are made from 316 stainless steel and have a temperature maximum of 90°C with pressures up to 5,000 PSI in custom configurations.

Load CellsThis non-contact method of measurement is typically used outside of a tank to measure its contents by weight and may be suitable when non-contact with materials being measured is required.

Ready to order? Have questions?

Whether you need a prefabricated float switch or a custom designed liquid level sensor, we can help! Our full OEM services are available whatever your industry and whatever your needs! Contact us today!

Liquid Level Sensors Help Farmers with Crops, Decrease Food Waste

Tomato crops

The agricultural industry is faced with many hurdles today. From changing weather patterns, to limited budgets, stringent guidelines as well as logistical and financial challenges, there is so much that goes into the food that ends up on our dinner plates.

One area where farmers must improve to start turning things around is related to the crops they produce. Better maintenance, greater productivity and less waste is critical.

Better Crop Maintenance

In some of the most important farming areas in the nation, the threat for drought has already created a stir around summer crop planting this year. Farms are having to make decisions about water use and soil monitoring so they can ensure necessary growth yields are met.

The need for more irrigation also increases spending and leaves less room for profits. To help curb this, tools that measure soil moisture and precipitation levels become critical for farmers. The continued quality control they provide– regardless of drought, supports growth throughout the season and for farmers, that’s a win-win.

Fluid switches and liquid level sensors find application within these tools. The sensors provide accurate measure of water being delivered to the plants and can sense how much is left for the soil to absorb.

Over watering can have just as bad an effect on crops, causing rot and not to mention, wasting water – which is both costly and bad for the environment.

Curbing Food Waste

Better crop yields also lead to less food waste – another threat we’re faced with today.

Waste in the form of less than perfect crops, deformed vegetables and those with abrasions getting left behind is part of the problem. Up to 20 billion pounds of produce are being left out in the fields and it’s happening on a grand scale.

That number is only part of the problem. When these crops make it to our dinner tables, even greater waste happens.

According to a research from the USDA, “30 million acres of cropland, 4.2 trillion gallons of irrigation water, 1.8 billion pounds of nitrogen fertilizer, and 780 million pounds of pesticides went into producing food that was thrown away.”

With tools to measure and maintain what’s being delivered to crops, it’s possible to create a better yield that farmers can sell. This type of precision agriculture is exactly what’s needed to curb food waste.

Solving Crop Insurance Woes

Finally, crop insurance is a giant industry. These policies help farmers to manage the risks they face due to Mother Nature and unpredictable weather changes. Without insurance, farmers risk the possibility of being shut down if a disaster occurs, but purchasing it is also costly.

With better tools in place to monitor the environment in a field, farmers can lessen the impact of weather extremes. Sensors that measure water provide data, monitor conditions and activate irrigation systems when needed. Together this helps to improve the landscape for today’s already burdened farming industry.

If you’re looking for a float switch or liquid level sensor, SMD Fluid Controls has a variety to choose from and can even build custom applications. Contact us today and we’ll help you find the best sensor for your project.

Clean in Place: Keeping the Dairy Industry Sanitary


The dairy industry is a vital part of the global food system. Milk provides necessary nutrients to families and many of its byproducts are the key component in a balanced diet.

In a large scale production setting, there are not only strict guidelines when it comes to storage, collection and pasteurization of milk from cows, but farmers must also utilize new technologies and innovations to keep up with demands.

Chief among these needs is the assurance that sanitation is happening and that products are safe for human consumption.  Working closely with the Food and Drug Administration (FDA), the industry has maintained their status as one of the most hygienic practices in the nation.

Safety in Food Production

Today, milking cows has become an exact science for farmers. To yield the best results, they are closely monitoring and testing from the milking process all the way through to the production. Much of this monitoring checks for quality and aims to prevent diseases transmitted by food.

A large part of this prevention comes from properly washing equipment used in the production process.  A system known as Clean in Place (CIP) is critical for the dairy industry as it makes quick, proper cleanings of the interior of vessels, tanks and lines, possible.

Clean in Place (CIP) for Dairy Farming

CIP systems are commonly used in manufacturing settings, especially in dairy production, as they are the only way to assuredly clean and sanitize equipment used in food production.

Equipment with sensors that accurately measure and sense liquid presence or absence are essential to the continued success of the dairy industry.

These systems use water, heat and/or chemicals to clean and sanitize and remove dirt, spores and other bacteria, both visible and not visible, to guarantee cleanliness. Fluid presence in tanks as well as their levels and temperatures are also measured to ensure proper cleaning and sanitation per stringent industry guidelines.

Through the use of accurate sensors, the system also eliminates the need to dismantle equipment each time and speeds up production times without putting health at risk.

SMD Fluid Controls provides prefabricated and custom float switch and liquid level sensors in full OEM services and designs or we can design and supply machined level sensors or custom molded float switches in a large variety of metals or plastics.

Contact us today to get started!

SMD Fluid Controls Announces Updated Certification of ISO Standards

quality certification

The International Organization for Standardization (ISO) sets specifications and guidelines in place for everything from manufactured products and technology to food, agriculture and healthcare.

The standards take into account characteristics of the process, materials and products used to ensure that safety and quality standards are met.

ISO standards are also set-up to provide organizations with solutions that increase productivity and reduce errors and waste at their operations. These standards are regularly reviewed and updated as new requirements are created to meet marketplace changes while ensuring the needs of customers.

SMD Fluid Controls recently updated its ISO standards to continue its focus on manufacturing quality liquid level sensors for international use across industries.

The most recent certifications, ISO9001:2015 and ISO 13485:2016 are applicable to the design and manufacture of sensors, flow and strain gauges used to measure force, pressure, liquid level, flow and other parameters.

Specifically, ISO 13485 is for Medical Devices while ISO 9001:2015 is a generalized standard of compliance of quality management principles.

These latest certification update means optimal quality control is happening at the operations and that regulatory requirements are being met in the manufacturing of medical devices.

“Being ISO certified lets our customers know that we are a capable sensor manufacturer that provides a quality product that meets our customer’s specifications. It also provides proof that we are continually investing in improving to meet and exceed our customer’s expectations,” commented Dennis Adams, Product Manager & Sales Engineer at SMD Fluidswitch.

Have questions? Need help choosing a sensor that fits your needs?

SMD Fluid Controls serves a diverse range of industries and can consult with you to recommend the most effective and efficient industrial float switch and liquid level sensor solution for your application. Contact us today.

Optical Level Sensors for Leak Detection

Industries today are under constant demand to deliver always on and always reliable services – regardless of environment. To assist them with this task, many are relying on technologies that monitor and accurately measure the solutions and systems that are critical to their operations.

This type of accuracy and monitoring while advantageous for some, is absolutely critical in industries like .

What are Level Sensors?

Level sensors in a very basic sense do exactly what the name implies- measure the amount of substance contained in a vessel, vat, container or other apparatus. Typically a separate system is used to get the results of what the sensors are measuring and from that data, it’s possible to uncover whether or not further action, dangers or any other outcomes will occur.

optical level sensorHow are Optical Sensors Used?

While there are different types of sensors used for various types of liquids and other substances, optical level sensors can detect and sense different types of liquids that do not dissolve when together (like oil and water). The optical switches operate off of an infrared LED that checks for changes in the light’s transmission (reflection) to detect and confirm changes.

Advantages for Leak Detection

Since optical liquid sensors operate well in any size tanks, they are a go-to option for leak detection. The monitoring and prevention of leaks is critical for service interruptions, to protect equipment and is critical to many industries. From damage caused by mechanicals running dry, or water and oil spillage from leaks, the needs are varied.

As the importance of these sensors grows, the market will continue to increase in demand. Market projections from Research and Markets show the level sensor market will reach $5.32 billion by 2023.

SMD sensors are a great choice due to their superior accuracy, reliability, and long-term stability in harsh environments. Our optical liquid level sensors can be used for sensing in water and numerous other liquids to attain precise measurements.

Contact us to find out more and schedule a free consultation.

SMD Fluid Controls Named a “Key Vendor” in New Worldwide Market Report

a series of analytics In less than two years, SMD Fluid Controls has three times been named a major player in the global float switch marketplace.

Related Posts:

Most recently, Technavio’s report, Global Float Switch Market 2017-2021, named SMD Fluid Controls as one of the “key vendors in the global float switch market.” Continue reading

Liquid Level Sensors with No Moving Parts

the surface of water

For many people, “liquid level sensor” is synonymous with “float switch.”

Traditional float switches work thanks to a magnetic reed, breaking or connecting an electrical circuit when liquid levels reach a specified point via a specialized float.

For most applications where liquid levels need to be measured within a tank or other vessel, float switches work perfectly, especially considering the variety of custom options—mounting position, chemical compatibility, and more. Continue reading