Remedy: Select diaphragm #3 (open) to see the
full Turpol field, and correct pointing to bring the star into the diaphragms
(positions should be marked on the laptop screen). If no star is seen,
re-point the telescope and try again. Make sure that it is not clouded.
Check that the mirror switch is pointed to VIS and not to TV (but be careful
with the switch). If source is bright enough for guide TV, put the guide
probe to center position (g-p-c) on the TCS, and see if the object
lands on the mark made by staff. If there is no object, something is wrong.
If the object is too faint for the guide TV, try to image the field with
StanCam before calling staff. On the TCS set c-p-c to move the
StanCam pickoff mirror into the beam, and foc-del -1175 to adjust the
telescope focus. NB! Remember to adjust the tv-focus to keep on guiding and
re-adjust both when finished!
Problem: PP program crashes (does not respond).
Remedy: Reboot the Turpol computer (Miriam) either by
Ctr-Alt-Del, pushing the reset button or power-cycling it.
Note that no data is lost. Restart PP and open the same data file.
Problem: Error message: 'Retarder found in wrong
Remedy: The stepper motor might have lost one
or more steps, but the effect in the measured position angle is usually
negligible (a fraction of a degree), and message can be neglected. The
retarder is automatically put in the correct position at the start of
each measurement cycle (i.e. each set of 8 measurements).
Problem: Turpol does not start integrations.
Remedy: Turn off and on again the chopper.
For staff: Make sure that IRQ9 is not reserved in the BIOS settings (Power
management setup -> Reserve IRQ 9 = NO). See also
Turpol setup procedures.
Problem: Error message: 'TPM channel 2 timeout.'
Remedy: Turn off and on again the chopper until
the PP program starts without this error message.
Problem: Uneven light distribution from the diaphragm illumination.