Chromatography Forum

Hi,
We are using a Waters 2475 fluorescence detector, recently the flow cell was damaged (high pressure). The cell was replaced but we are getting a message after "Searching Zero Order Peak" startup diagnostic. The message is "Peak not found Excitation Zero (0.00)". The lamp is new and it is turning on. Which parts of the optics can be causing the problem?

Hi,
We are using a Waters 2475 fluorescence detector, recently the flow cell was damaged (high pressure). The cell was replaced but we are getting a message after "Searching Zero Order Peak" startup diagnostic. The message is "Peak not found Excitation Zero (0.00)". The lamp is new and it is turning on. Which parts of the optics can be causing the problem?

I think the excitation monochromator needs manual calibration. By zero order, the detector searches for the reflected peak from the slit next to the lamp i.e. it is looking for the reflected beam from the lamp without undergoing diffraction. If the grating angle changes, by some means, you will get this error on any optical monochromator. This can also happen if the lamp is not aligned wrt to the entrance slit.