SICK OD7000 Prime, Operating Instructions Manual

Page: 44 / 64

8 Operation
8.1 Positioning measuring head
Important information
NOTICE
Damage to the measuring head
The optical components in the measuring head can be damaged by incorrect handling.
•
Do not twist the upper and lower halves of the measuring head against each other.
•
To fasten the measuring head, only hand-tighten the clamping screw.
Prerequisites
• The device is connected.
• The measuring head is connected.
Approach
1. Align the measuring head perpendicular to the measuring object.
2. When using a clamping device: Clamp the measuring head.
3. Gradually change the distance from the measuring head to the measuring object
until the intensity is maximum (coarse adjustment).
4. Find the point on the measuring object with the smallest distance to the measur‐
ing head.
5. Check the spectrum. Change the distance of the measuring head so that the peak
is at the left end of the spectrum (fine adjustment).
✓
The measuring head is positioned at the correct working distance.
✓
If the measuring position is changed, valid distance values are measured.
Further topics
• Working distance and measuring range
8.2 Performing dark balance
Overview
Even if there is currently no sample within the measuring range, the detector of the
device receives signals. These signals are generated by stray light in the fiber coupler,
reflections from the fiber connectors, ambient light, and noise from the detector. The
higher the intensity of these dark signals, the more the measuring capability of the
device is limited.
The influence of the dark signals can be minimized by a dark balance. A dark calibra‐
tion is performed at the factory for each device before delivery. However, the dark
balance must also be performed by the user in certain situations.
When must a dark adjustment be performed by the user?
•
Before new measuring tasks
•
After changing the measuring head
•
After changing the optical fiber
•
In case of unusual measurement results, e.g. due to contaminated fiber ends
The dark balance value depends on different factors e.g. light source, spectrometer or
condition of the optical fibers. Therefore, no guideline value can be given that must not
be exceeded during dark calibration.
8
OPERATION
44 O P E R A T I N G I N S T R U C T I O N S | OD7000 8027188//2022-05-25 | SICK
Subject to change without notice