The brewer spectrometer has two internal lamps for diagnostics and operational use.

• Standard Lamp (SL)
• Mercury (HG)

One of the purpose of of the standard lamp is to determine the R6/R5 value which is used as part of the calculation to determine the total column ozone. This can be measured by running the SL command. For double spectrometer (MkIII) the standard lamp is also used to find the optimal position for the micrometer to get the highest intensity output. This can be done by running the command HP.

1. Perform the following command and note and variation in R5/R6 over 20/10 units

   MKII/MIV

   pdfrhghgslslspd

   MKIII

   pdfrhphghghphgslslslpd

2. Turn on the SL bulb on with B1, do a ZE to point the prism toward the lamp and check the position of the bright band of light against the closed iris in the viewing port.
3. Put on the safety glasses
4. Remove the bulb holder from the housing and inspect the filament.
5. Note if quartz is cloudy/milky or if it is dark/gray. Non-transparent quartz can affect HG!
6. Turn the lamp off with B0
7. Replace the lamp
8. Turn the lamp on with B1
9. Ensure the brightest band of light is over the closed iris. Adjust the ZE offset if required
10. Run the following command and note any changes in R5/R6

    SLSLSL

This is used to determine the operating position where the instrument measures at. Operation position is temperature dependent and will change with the temperature. The measurement is done via the HG command. During most schedule, HG will run every two hours or when the temperature has changed more then 2c.

1. Perform the following command and note and correction that the software applied to the micrometer position

   MKII/MKIV

   pdb1frhghghg

   MKIII

   pdfrhphghphghphg

2. Turn on the HG bulb on with B2
3. Put on the uv safety glasses
4. Remove the bulb holder from the housing and inspect the filament. Note any excessive sagging or if the filament is touching the holder prongs.
5. Replace the HG bulb ensuring the brightest spot is on a 45 degrees angle with respect to the alignment pin.
6. Put the bulb back into the housing.
7. Perform an HG and note micrometer shift.
8. Run 2 more HG to ensure the new position is repeatable.

• B0 - Turns off the HG and SL Lamp
• B1 - Turns on the Mercury Lamp
• B2 - Turns on the SL Lamp
• HG
• HP
• SL