Bio-Rad Model EM-1 Econo™ UV Monitor - Manual (Page 15)

12
Avoid letting the flow cell become dry, as dissolved solids may pre-
cipitate and attach to the walls. This will result in baseline drift and pos-
sibly a noisy signal.
If the flow cell becomes dirty, it should be cleaned with an appropriate
solvent. (SDS, 1M HCl, 1M NaOH, ethanol, acetone, and methylene chlo-
ride will not harm Model EM-1 Econo UV Monitor flow cells.) If NaOH
is used, it should not be left in the flow cell for more than 20 minutes.
The control unit may be left on continually (power consumption is
negligible).
Section 8
Troubleshooting
Problem Possible cause Solution
Base line drift Bubbles in flow cell Clear by using pump
or purge mode, and inter-
noisy signal mittently pinching the
outlet tubing, holding
momentarily, and
releasing.
Insure that flow
direction is correct.
Use degassed buffers.
Lamp not warmed up Wait 20 minutes
before use.
Filter tray is loose Adjust fixture screws;
Flow cell is loose these components
Case screws are loose should be snug, not
tight.
Dirty flow cell Clean flow cell; insure
that buffers are free of
particulate material.
Aging lamp Replace lamp (see
Appendix B). Note:
When using the 254 nm
filter, the lamp LED will
blink before baseline
becomes noisy.
M7318160G.qxd 05/08/2003 2:05 PM Page 12