2019-09-30 FOCALSPEC User quide LCI1220-1620 v1.0
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FocalSpec Oy • Elektroniikkatie 13, FI
-
90590 Oulu • www.focalspec.com
Figure 2. Timing diagram of a quadrature encoder.
11
Sensor Warming Up
Warming up the sensor is recommended prior to data acquisition in order to stabilize the
sensor’s capability to measure absolute Z coordinate. During the sensor’s warmin
g up
there is a small variation on the absolute Z height on which the sensor sees the target
surface.
The recommended warm up time is 30 minutes with 50% duty cycle. 50% duty cycle can
be achieved e.g. using LED pulse width 1 ms and frequency 500 Hz.
In general, it is recommended to use relative Z coordinate for measuring rather than
absolute. In relative measuring the used Z height value is the difference to the
reference, not an absolute Z value. This way the set-up is less sensitive to any variation
over time like vibration or ambient condition changes.
12
Preparing Measurement Setup
To ensure the most favorable measurement conditions, follow the instructions below.
•
Handle the sensor with care. Neither the casing nor the lenses of the sensor must
interfere with any object: only the dedicated mounting holes are to be used when
installing the sensor.
•
Do not hit, drop or shake the sensor. The optics may get out-of-tune if the sensor
is handled improperly.
•
If the sensor cannot yet be mounted into your setup, it should be laid on top of a
clean, sturdy table.
•
If you need to clean the lenses, please use compressed air (hand-help bottles are
usually enough). If compressed air does not remove the impurity, dedicated lens
cleansing liquid and cloths should be used with care.
•
The target on the reference sample holder must not be touched. Keep the sample
clean and if needed, use compressed air for cleaning, do not use liquid, etc.