| Symptom |
Possible Problem |
Solution |
| Lamp difficult to light |
Old lamp(1,000 hours) |
Change lamp |
| Current control on power supply |
Increase power supply current |
| Lamp shuts off repeatedly |
Bubble in cooling box fluid |
Use "burper bottle" to remove air from system |
| PEM Error |
Hinds PEM unit is not powered or connected to C4 on A/D board (computer) |
Turn Hinds unit on and ensure connections are secure |
| PEM HV increases to Maximum (1100 V) |
PMT detectors seeing no light |
Ensure the lamp is on |
| Slits are open |
| No inappropriate filters are in place |
| The sample is not opaque at the current wavelength |
| Very high PMT HV in far UV |
UV-absorbing buffer components |
Remove UV-absorbing components |
| Old lamp |
Replace lamp |
| Too much oxygen in system |
Increase nitrogen purging |
| Irreproducible signal intensities |
Sample sticking to cuvette |
Clean cuvette |
| Increase concentration |
| Change buffer components to avoid sticking |
| Sample degraded by measurement beam |
Reduce slit width |
| Reduce measurement time |
| Increase sample concentration |
| CD intensity not correct (or upside down) |
Phase adjust incorrect |
Change phase adjust value to give maximum signal |
| PMT cables reversed |
Plug in cables correctly |
