Photodiode Sensors
StarBright User Manual
42
AUTO
: Select autoranging when the laser power is unknown or varies widely. In autorange,
you do not have to change scales. (The reading is displayed in watts.) This change only
occurs after a few seconds delay. This provides overlap (hysteresis) to keep the StarBright
from flipping back and forth when reading close to the end of the scale.
Manual range
: The correct manual range is the lowest one that is larger than the expected
maximum power of the laser. There are certain disadvantages to autorange, since it
changes scale even if you do not want it to do so. If you want to measure in the same
range all the time, it is better to use a manual range.
3.
Set
Wavelength
to the correct laser wavelength. If the laser’s wavelength is not listed, select
any of the options and press
Modify
. Using the up/down Navigation keys to change each
number and the right/left keys to move to the next number, key in the wavelength you want.
(The Spectral range is
200 to 1100
.) When finished, press the
Enter
key.
Figure
7-1 Modifying the Wavelength – Photodiode Sensor
4.
Set the removable
Filter
setting to
IN
to measure higher power or to
OUT
for more accuracy
and a wider wavelength range—as physically configured on the sensor. See
and
. Make sure to physically insert/remove the Filter before continuing
measurements. For sensors with built-in filter state detection, only the present state of the
filter will be shown to the user. It will be updated in the event that the filter state is physically
changed, thereby causing the sensor to report the new filter state to the meter.
Warning:
If the PD300 is used in the "Filter IN" setting and the filter is not installed, or vice
versa, the readings will
be completely
incorrect. If the power of your laser exceeds the
maximum for filter in, you can purchase a Thermopile or integrating sphere sensor for that
wavelength. Consult your Ophir agent for details.
5.
Set
Average
to the period you wish to average power over or set to
NONE
to disable. This
feature is especially useful for lasers with unsteady output. (The Average can also be
configured in the Functions screen.)
Note:
The
Average
function does not work with autorange or dBm scales.