Hinds Instruments EXICOR 150AT, User Manual, Page: 32 / 95

Chapter 3: Operating The System
22 Exicor 150AT User Manual
Warm-up Time
The system needs to be powered on for at least 30 minutes prior to making
measurements. As the laser inside the source module warms up, its intensity
increases then becomes steady after about 30 minutes.
Offset Measurements (Zeroing the System)
In order to maintain the low level measurement accuracy and sensitivity, the system
must be “zeroed” periodically. For this process the system analyzes the detector
signal with no sample or other obstructions in the beam path and uses this condition
as a base line for future measurements.
The appropriate time period for taking offset measurements will vary by application.
If very low retardation samples are being measured (retardation < 5 nm), it is
recommended to take offsets before each scan and every 20 minutes thereafter in
most cases. If high retardation samples are being measured, the time between
offsets can be longer.
There are 2 options for taking offset measurements: manually and automatically.
Both methods require the beam to be unobstructed during the process. To take a
manual offset, simply move the stage so that the laser beam is not obstructed and
click . The automatic offsets function will always take an offset before each scan
then periodically take offsets during the scan as well. To take offset measurements
automatically, the user must define the settings of the auto-offset measurements as
described on page 38.
Loading a Sample
Load a sample onto the system by placing it in a special holder to be mounted to the
top plate of the X-Y stage. Sample holders can be fixed to the stage using the
threaded holes provided in the top plate.
See Figure 3.2 below for the dimensional information and mounting features of the
X-Y stage.