Teledyne Princeton Instruments PICam 5.x, Руководство программиста

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Chapter 8: EM Calibration APIs
This chapter provides information about the EM gain calibration APIs. All functions, data
definitions, and structures are located in the
picam_em_calibration.h
file.
NOTE:
The information and APIs described within this chapter are
NOT applicable to
em ICCD cameras.
8.1 EM Calibration Applications
Each ProEM or Evolve camera is factory-calibrated for linear EM Gain. Over time,
however, aging of the EMCCD array may degrade gain linearity. Because aging appears
to be a strong function of the amount of charge that flows through the multiplication
register, users who consistently operate the camera at high gain at high light levels may
need to recalibrate EM gain more frequently than those who are looking at lower light
levels at lower gain.
To compensate for aging, each ProEM or Evolve includes a built-in shutter (either
manual or electro-mechanical) and a light source that allows users to perform on-
demand EM Gain Calibration using a calibration application. Once the EM gain
calibration has been performed, the gain value entered in the software by the user will
be the actual multiplication gain applied to the input signal.
CAUTION!
!
When calibrating a ProEM or Evolve camera with a manual
shutter (e.g., ProEM:1600,) the shutter MUST be closed
manually before launching any calibration program.
This is not necessary for a camera with an internal electro-
mechanical shutter because the program will automatically
close the shutter before beginning the calibration.
PICam users have two options available when creating an EM Calibration application:
• Build the sample code
EMGainCalibration.exe
that is included with PICam.
This option requires the least amount of development time and overhead since
EMGainCalibration.exe
is a fully functional application once it has been built.
REFERENCES:
Refer to Appendix B, EM Gain Calibration Code Sample , for
additional information about using the sample code.
• Create a custom EM Calibration application using the API routines, structures,
and callbacks described in this chapter.
When building a custom application, the
EMGainCalibration.exe
sample code
included with PICam is a good resource for the developer when learning about
the EM Calibration API library.