Each Wasatch Photonics spectrometer contains an EEPROM (Electrically Erasable Programmable Read-Only Memory) which stores configuration information about the device.
Key EEPROM fields include:
- Serial number
- Excitation wavelength (internal laser models only)
- Wavelength calibration (3rd order polynomial)
- Detector temperature calibration (2nd order polynomial)
- Detector setpoint calibration (2nd order polynomial)
- “Bad pixel” list
For a full list of EEPROM fields, see Wasatch Photonics document ENG-0034.
Future versions of ENLIGHTEN™ will allow authenticated operators to update select configuration fields by writing to the EEPROM.
5.3.1 Gain and Offset Correction
All spectra read from the spectrometer are automatically corrected for signal gain and baseline offset based on values stored in the FPGA. These values are not user-changeable via the ENLIGHTEN™ application, although gain can be set temporarily via the .ini file (see Appendix C).
5.3.2 Bad Pixel Correction
Spectrometer detectors, like any digital camera or LCD display, may occasionally develop one or more “bad pixels”. These pixels may be dead (low/no signal), or “hot” (unreasonably high signal). When bad pixels are identified, their indices are stored in the spectrometer’s EEPROM. ENLIGHTEN™ reads their locations at application startup, and automatically corrects read spectra by averaging-over the bad pixel with a linear average of adjacent good pixels. This function prevents one or more malfunctioning pixels from affecting data quality.
Future versions of ENLIGHTEN™ will allow users to disable bad-pixel correction in case raw detector data is desired.
5.4 .INI Configuration
Settings stored within your spectrometer’s EEPROM will be temporarily overridden while using ENLIGHTEN™ if there is a corresponding section in your .ini file which matches your spectrometer’s serial number. See the for additional information regarding .ini file location and contents.