NSD - Economical Optical Level Switch

Brand: KOBOLD Instruments, Inc

The NSD optical level switch is a low cost solid-state level sensor suited for clear, translucent, and non-coating low viscosity liquids. 

This level switch functions by detecting the difference in refraction between the liquid and air. 

An infrared LED inside the lens transmits a beam of invisible light. 

In air, the beam is reflected back into the sensing circuit to an infrared detector. In liquid, the beam is refracted away from the detector and results in switch activation or de-activation depending on the switch logic as ordered.

The NSD is available in polysulfone, or 316 stainless steel with a polysulfone lens. 

The switch output is a PNP open collector with normally closed (activated) dry or normally open (deactivated) dry logic, depending on the model code. 

A red LED status indicator is lit when the switch is activated.
  • PNP Open Collector Output Standard
  • Polysulfone or Stainless Steel Body
  • OEM Targeted Product
  • Low Cost and Reliable Optical Sensing Technology
  • LED Status Indicator
  • Overcurrent and Reverse Polarity Protected


Suitable Media

  • Compatible Low-Viscosity, Clear and Non-Coating Liquids


  • 3/8” NPT

Body Material

  • 316 Stainless Steel
  • Polysufone

Electrical Protection

  • NEMA 6/IP68

Maximum Pressure

  • Polysulfone: 140 psig
  • Stainless Steel: 550 psig

Temperature Range

  • 15° F to 250° F


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