trouble using dual detection mode of Waters 2487 detector

[pri6886]

Hi , I need to perform HPLc measurements at 270 nm and 420 nm
I am using the Waters HPLC apparatus equpped with Waters 2487 detector for this.
However the problem is that whenever I use a method using the detector at more than one wavelengths, then the chromatograph obtained seems to be wrong.
i.e within the first 1 min, i get a baseline for the first 10 minutes, then in the 11th minute i get a baseline for 10-20 mins, in the 21st minute, I get a baseline between 20 mins-30 mins.. and so on...

i cannot understand how I am getting chromatograph for 10 minutes, when I have run the machine for only 1 minute..?

This problem is not observed when using the detector at single wavelength.
When using a single wavelength, I get a chromatograph as the HPLc run progresses.

[remesquaddie]

It's very likely the method needs a second look, and check to make sure that the instrument method includes the two channels turned ON. '

Hi , I need to perform HPLc measurements at 270 nm and 420 nm
I am using the Waters HPLC apparatus equpped with Waters 2487 detector for this.
However the problem is that whenever I use a method using the detector at more than one wavelengths, then the chromatograph obtained seems to be wrong.
i.e within the first 1 min, i get a baseline for the first 10 minutes, then in the 11th minute i get a baseline for 10-20 mins, in the 21st minute, I get a baseline between 20 mins-30 mins.. and so on...

i cannot understand how I am getting chromatograph for 10 minutes, when I have run the machine for only 1 minute..?

This problem is not observed when using the detector at single wavelength.
When using a single wavelength, I get a chromatograph as the HPLc run progresses.