Gentec-EO MAESTRO - Manual (Page 18)

MAESTRO User’s Manual Revision 8.1 17
Adjusting the zero (step 8a for power heads and 8b for photodiode heads)
8- The power read by the MAESTRO when no laser beam is incident on the detector may not be
exactly zero. For power measures, this is because the detector is not thermally stabilized OR
there was a heat source in the field of view of the detector when you turned on the MAESTRO.
As for photodiode measures, zeroing will remove
the detector’s offset.
a. Block off laser radiation to the detector. To reset the zero, wait until the reading
has stabilized and touch Zero in the parameters menu. Two options will appear
(On or Off), select On. You are now ready to take an accurate measurement. To
turn the Zero Offset off, select Off.
Fig. 2-3 Parameters menu to set the detector’s zero level
b. If you have connected a photodiode to the MAESTRO, you must cover the diode
and the zero has to be done for all scales. You will not have to do this manually
for each scale as this is automatically done when you turn
“on” the zero. In some
software versions, a message appears requesting you to put the black cover over
your photodiode. Touch the OK button after you have done so. The MAESTRO
passes through all the scales to determine the zero diode for each scale. The
message “Diode Zero Done” appears when the MAESTRO has determined the
zero diode.
Notes:
• Refer to specific power detector documentation for complete installation and operating
instructions.
• Power detectors are thermal sensors and are thus sensitive to temperature variations.
For high-precision measurements, it is recommended to:
• Allow the power detector temperature to stabilize before zeroing the MAESTRO.
• Touch only the stand when handling the power detector. Do not touch the detector head.
• Do not zero adjust the energy detectors, such as the QE series.

Avoid forced airflow or drafts around the detector.