Series-OLS

Supported Applications

The Dwyer Series OLS Optitrol® Optical Level Switches are compact, rugged devices designed to indicate the presence or absence of liquid using infrared light reflected through a prism lens. The series is specified for noncoating compatible liquids and provides rapid response with no moving parts for stable process control.

Key operational features include:

• Detection via an infrared LED and photo-transistor assembly
• Bright red and green LEDs indicating liquid presence or absence
• No minimum specific gravity requirement

Operating Conditions & Performance

The Series OLS operates within defined temperature, pressure, and environmental limits that vary by model. The switches are rated for a power supply of 10 to 28 VDC with a maximum current consumption of 35 mA.

• Process Temperature: Models OLS-10 and OLS-11: 200°F (93.3°C); Model OLS-12: 120°F (48.9°C)
• Ambient Temperature: Models OLS-10 and OLS-11: 175°F (79.4°C); Model OLS-12: 120°F (48.9°C)
• Pressure Limit: Models OLS-11 and OLS-12: 200 psig (13.8 bar); Model OLS-10: 1000 psig (69 bar)
• Repeatability: ±0.02" (0.5 mm)

The unit weighs 3 oz (0.085 kg). Installation requires the prism surface to be at least 2" from any reflective surfaces and away from infrared light sources.

Configuration Options

The series is available in three material configurations tailored for different service environments, all featuring a standard process connection of 1/2" male NPT. Electrical connections are provided via a 38" (965.2 mm) 3 conductor cable with 22 AWG wire.

Model Configurations

• OLS-10: Wetted materials of 316 SS/Polysulfone; rated for pressures up to 1000 psig (69 bar).
• OLS-11: Wetted material of Polysulfone; rated for pressures up to 200 psig (13.8 bar).
• OLS-12: Wetted material of PFA; rated for pressures up to 200 psig (13.8 bar) and temperatures up to 120°F (48.9°C).

Output & Mounting

• Switch Type: NPN open collector with Vout (max) = 28 VDC, Isink (max) = 100 mA.
• Mounting Orientation: Horizontal or up to 45° from horizontal only. Note: While the data sheet states "Can be mounted in any position," the instruction manual explicitly restricts mounting to "Horizontal or up to 45° from horizontal ONLY."

Key Product Differences

The primary distinction between Series OLS models is the wetted material composition and the resulting pressure/temperature ratings. The OLS-10 utilizes a stainless steel construction for high-pressure applications, whereas the OLS-11 and OLS-12 utilize plastic materials (Polysulfone and PFA) suitable for lower pressures up to 200 psig.

Model selection is driven by media compatibility requirements: Polysulfone or PFA may be selected based on chemical resistance needs, while the 316 SS/Polysulfone combination in the OLS-10 supports higher pressure service. All models share identical electrical specifications and output signal characteristics.