Chromatography Forum

Dear all,
we have an thermo surveyer HPLC system with PDA and RI detector.from last one weak Our RI system is showing some error light intensity is too low and in status it showing error.Voltage is around 3.5V.We are purge the system all night with water and doing some calibration with sucrose solution.But now also error.Please give some advice for rectify the problem.

A few possibilities come to mind:

- the flow cell may be dirty. Perhaps flushing with dilute nitric or phosphoric acid followed by DI water and then methanol (check with Thermo for recommended cleaning procedures)

- Mirror surfaces may be dirty or corroded (I'm not sure if than model uses any mirrors in the optical path). A visual inspection of the mirror surfaces should answer that question. If dirty, a cleaning with methanol may help. If corroded, replacement will be necessary (again, check with Thermo first for recommended procedures).

- Lamp may be dying. Replace.

Wash both the reference cell and the sample cell with water then with IPA at least 10 minutes , at 1ml/min flow.

After that , zero the detector , and check if the problem is solved.