An optical fluid level switch does not measure the liquid level, instead they detect the presence or absence of liquid. When selecting the correct fluid level sensor for your application, it can be difficult at times as there are so many options available. This article provides the necessary information you need to know when selecting any of PST’s fluid level switches.
Before researching all the sensor types that PST has to offer, it is important to look at the bigger picture and understand where and how the sensor will be used. This means looking at where the sensor is going to be mounted, the application requirements and environmental factors. These are explained below.
Mounting position: where the sensor is to be mounted can narrow the selection field, for example, is space a restrictive factor?
Application: where the sensor is to be used can narrow the selection field:
Food or beverage application?
Medical or chemical handling?
Environmental factors; the environment in which your sensor will be working has a direct bearing on the material type you should select. Fluid type and temperature are key factors; for example, is the liquid corrosive; high or low temperature?
Following on from this, the next few steps is to narrow down the number of options available to you.
Step 1 - Sensor Material
It is important to consider what material is more than likely going to suit your mounting, application and environmental requirements. Does it have to withstand corrosive liquids, extreme pressure or temperatures?
Please note: when making your selection that the body of some of our fluid level sensors are made from a different material to the sensor tip.
PST offers three housing material options depending on fluid sensor type: Polysulfone, Trogamid® (EU food-contact grade) or stainless steel. Again, depending on sensor type, PST offers three tip material options: Polysulfone, Trogamid® (EU food-contact grade) or glass.
Step 2 - Sensor Types
This is the step where you look closely at the sensor specifications and make sure it is going to be suitable for your application environment.
There are six fluid level switch ranges within the liquid level family: Optomax Digital, Optomax Industrial, Optomax Industrial Glass, LLHP, POS and Optomax Basic. The following gives a brief overview of each sensor and why they differ from each other based on operating voltage, temperature range and application.
Optomax Industrial Glass
LLHP (High Performance) Series
Step 3 - Select and Test
Once you have narrowed your selection down to one or two products that may be of interest, PST recommend to test a sample of the product to ensure it will work in your application. We normally recommend testing the product, fully submersed in the liquid at maximum temperature for 2 weeks. If at any point you are unsure of what fluid level sensor is going to be suitable for your application, our team of engineers provide full application and technical support on all of our products and would be happy to assist in choosing the right sensor that will meet your requirements.