Glossary for detailled explanation - take your pick:
see also: Operating Voltage Ub
Non Flush Mounting
Surface mounted sensors have a higher switching distance than identically constructed flush mounted devices and are not surrounded by a metall housing in the area of the active
surface. Therefore, the active surface of a surface mounted sensor has to stand out at least 2x Sn from the metallic mounting space. The distance to faced metallic surfaces mounts ≥ 3 x Sn and to faced or in parallel mounted sensors ≥ 3 x diameter.
Normally Closed (NC)
The sensor output is interconnected and the load current Ie flows when NO object is detected within the measuring range of the sensor. For optical sensors, this break function is called "dark switching" in accordance with DIN 44030.
Normally Open (NO)
The sensor output is interconnected and the load current Ie flows if an object is detected within the measuring range of the sensor. For optical sensors, the switching function is called "light switching" in accordance with DIN 44030.
The output stage contains a NPN transistor that connects the load to the negative operating voltage (OV). The load is installed between the output and the positive operating voltage (+Ub).