Page 22
Installation
optoNCDT 1420
5.
Installation
5.1
Instructions for Installation
5.1.1
Reflection Factor of the Target Surface
In principle the sensor evaluates the diffuse part of the reflected laser light.
Laser beam
Ideal diffuse reflection
Real reflection
Direct mirror reflection
Laser beam
Laser beam
2
Fig. 8 Reflection factor of the target surface
A statement concerning a minimum reflectance is difficult to make because even a small diffuse fraction can
be evaluated from highly reflecting surfaces. This is done by determining the intensity of the diffuse reflection
from the CMOS signal in real time and subsequent compensation, see Chap.
3.2
. Dark or shiny objects being
measured, e.g. black rubber, may require longer exposure times. The exposure time is dependent on the
measuring rate and can only be increased by reducing the sensor’s measuring rate.
5.1.2
Error Influences
5.1.2.1
Light from other Sources
Thanks to their integrated optical interference filters the optoNCDT 1420 sensors offer outstanding perfor-
mance in suppressing light from other sources. However, this does not preclude the possibility of interference
from other light sources if the objects being measured are shiny and if lower measuring rates are selected.
Should this be the case it is recommended to use suitable shields to screen the other light sources. This ap-
plies in particular to measurement work performed in close proximity to welding equipment.
Summary of Contents for ILD 1420-10
Page 8: ...optoNCDT 1420...
Page 121: ......
