User guide

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.

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