NSD OPTICAL SWITCH OPERATION MANUAL
PRINCIPLE OF OPERATION
The optical switch operates by the principle of Snell's law: When
light moves from a medium of a given refractive index (n1) into a
second medium with refractive index (n2), both reflection and
refraction of the light may occur. An incident light ray strikes at a
point on the interface between two media of refractive indices n1
and n2. Total internal reflection is an optical phenomenon that
occurs when a ray of light strikes a medium boundary at an angle
larger than a particular critical angle with respect to the normal to
the surface. If the refractive index is lower on the other side of the
boundary, no light can pass through and all of the light is
reflected. When light crosses a boundary between materials with
different refractive indices, the light beam will be partially
refracted at the boundary surface, and partially reflected.
Optical switches operate by sensing the difference in the
refraction index between various mediums, causing different
degrees of refraction and penetration. When the liquid is not in
contact with the sensor, all transmitted light is reflected back to
the receiver. When the liquid contacts the sensor, part of the
transmitted light is reflected back to the receiver and part is
emitted into the liquid. The receiver senses this difference in
signal loss and switches accordingly.
FEATURES DIMENSIONS
1. PNP Open-Collector Output
2. Housing Material: Polysulfone or 316SS
3. Over-current & Reverse Polarity Protection
4. LED status indication
SPECIFICATIONS
1. Housing Material: Polysulfone or 316SS
Sensing Tip Material: Polysulfone
2. Protection Rating : IP68
3 Process Temperature: 14-250 °F
4. Ambient Temperature: 14-175 °F
5. Max. Operating Pressure:
Polysulfone: 140 PSIG
316SS: 560 PSIG
6. Input Power: 10-28 VDC
7. Load Current: 100mA Max.
8. Overload Current Protection: 100mA
9. Process Connection: 3/8" NPT
10. Cable: 2 m PVC Jacket, 24 AWG, 3-conductor