Optical fluid level switches are designed to detect the presence or absence of liquid, rather than measure liquid levels. With a wide range of options available, selecting the correct fluid level switch for your application can be a complex task. This guide walks you through the key factors to consider and introduces the different product ranges offered by SST to help you make an informed choice.
Before You Choose: Key Considerations
To ensure the best performance and reliability, it’s essential to take a step back and consider the overall context in which the sensor will be used. Important factors include:
- Mounting Position
Where will the sensor be installed? Space constraints or the available mounting surface can help narrow down the most suitable options.
- Application Type
Understanding the industry or process is critical. For example:
- Is it a food or beverage application?
- Will it be used for medical devices or chemical handling?
- Environmental Conditions
Your sensor’s operating environment will determine suitable materials and specifications. Consider:
- Fluid type (e.g. corrosive or non-corrosive)
- Operating temperature range
- Pressure and exposure to chemicals
Step 1: Choose the Right Sensor Material
Depending on your application and environmental conditions, selecting the correct sensor body and tip material is crucial.
Available material options include:
- Housing materials: Polysulfone, Trogamid® (EU food-contact grade), or Stainless Steel
- Sensing tip materials: Polysulfone, Trogamid®, or Glass
Note: In some sensors, the body and tip may be made from different materials. Always check compatibility with your process media.
Step 2: Explore SST’s Fluid Level Switch Ranges
SST offers six ranges of optical fluid level switches, each with unique specifications tailored for different environments, voltages, and applications.
Optomax Digital
Compact and cost-effective for low-power applications
- Voltage: 4.5V – 15.4VDC
- Temperature: -25°C to +80°C or -40°C to +125°C
- Material: Polysulfone or Trogamid®
- Ideal for: Miniature sensing in confined spaces
Optomax Industrial
Designed for direct load driving and higher voltage systems
- Voltage: 4.5V – 15.4VDC or 8V – 30VDC
- Temperature: -25°C to +80°C or -40°C to +125°C
- Material: Polysulfone or Trogamid®
- Ideal for: Industrial systems with high power signal needs (up to 1A depending on output)
Optomax Industrial Glass
Built for harsh, aggressive environments
- Voltage: 4.5V – 15.4VDC or 8V – 30VDC
- Temperature: -40°C to +125°C
- Material: Stainless steel body with glass sensing tip
- Ideal for: High pressure/temperature, chemically aggressive environments
LLHP (High Performance) Series
Robust construction for demanding applications
- Voltage: 4.5V – 15.4VDC or 10V – 45VDC
- Temperature: -25°C to +80°C or -40°C to +125°C
- Material: Stainless steel body with Polysulfone tip
- Ideal for: Aggressive environments requiring multiple mounting thread types and higher switching currents
POS
Engineered for extreme conditions and aggressive chemicals
- Voltage: 12V – 28VDC
- Temperature: -25°C to +100°C or -40°C to +140°C
- Material: Stainless steel body with Simax crystal glass tip
Ideal for: Harsh industrial environments with extreme temperatures and chemical exposure
Optomax Basic
Analog output for OEM high-volume, cost-sensitive designs
- Voltage: 3.3V – 24VDC
- Temperature: -25°C to +80°C
- Material: Polysulfone or Trogamid®
- Ideal for: White goods, vending machines, automotive applications
Note: Requires a stable power supply and external microcontroller to interpret output.
Step 3: Select and Test
Once you’ve narrowed down your options, we highly recommend testing a sample sensor in your actual application. Our standard recommendation is to test the unit fully submerged in your process liquid at maximum temperature for a minimum of two weeks.
Need Help?
If you’re unsure which sensor is best for your application, our expert engineering team is here to help. We provide full technical and application support to ensure you choose the right sensor for your specific requirements.
