Float switches are used for a variety of applications, but no matter what they’re used for it’s always extremely important to measure liquid levels as accurately as possible. This is especially true if the float switch is used as a failsafe against overflow or other risks in high or low liquid level situations.
While the best way to ensure accuracy is always to use a precise, high-quality device, it’s also important that the switch is used for an application to which it’s ideally suited. If you know you need a float switch but aren’t sure exactly what to look for, take some of these considerations into account to get a better idea.
Do You Need a Horizontal or or Vertical Float Switch?
You need to establish what kind of vessel your float switch is going to be used with, where it’s located, what its shape is, and how deep it is. This will help determine whether you should use a vertical or horizontal float switch. For instance, a tank set into the ground with no side access will require a vertically mounted switch; a vessel that reaches from floor to ceiling would definitely need a horizontally mounted switch; a narrow, deep tank might be best served with a downhole submersible sensor.
Plastic or Stainless Steel?
You will also need to figure out what material is best suited for your specific needs. This will be determined by taking into account what kind of liquid the switch will be used with, as well as the temperature and pressure conditions. Stainless steel is an excellent choice for high heat and pressures, and its resistance to corrosion makes it ideal for food processing and other general industrial uses. Plastics are a good choice for less harsh media where acid might be present. The specific gravity of the liquid media will be a significant factor in deciding what material to use.
If you need your switch to activate when the tank is full and stop when the liquid level goes down, then you should look for a “pump down,” or normally open switch. If the reverse is true, you’re looking for a “pump up,” or normally closed switch.
Electrical considerations must also be taken into account. You want to make sure that your float switch can handle the voltage and current that your specific application will require. These are just some of the things you must keep in mind when selecting a float switch, and these are by no means step-by-step instructions. There’s no first and last step so much as a collection of factors that must be considered holistically.