Bandwidth on Agilent 1100 VWD

[Cliff Mitchell]

Does anyone know what the bandwidth is for an Agilent vwd detector. If you have the wavelength set at 254nm, are you getting 254 +/- 4nm? 10nm? 20nm?

Cliff

[pve]

a good question, Cliff
I add to this question: how do you choose the wavelengh for the reference, and what would be the bandwith for the reference?
Pierre

[Mark Tracy]

I don't know the answer to the first question (you could try Agilent's website), but the reference wavelength is always the analytical wavelength. The VWD uses a classic double-beam design where the monochromator is in front of the flowcell. A beam-splitter in between the monochromator and the flowcell sends a portion of the light to the reference photodiode. The bandwidth is set by the physical slits in the monochromator.

The diode-array detector uses so-called reverse optics where all wavelengths pass through the flowcell before going to the polychromator. The reference wavelength is always different than the analytical wavelength in this design, and you can choose what it will be. The bandwidth is set in software by summing together the diodes around the selected wavelength.

[AA]

Specifications - 1200 Series Variable Wavelength Detector
Wavelength bandwidth 6.5 nm typical over whole wavelength range

Agilent seems to have removed all the spec sheets that reference the 1100 series modules. As far as I know the 1200 Series Variable Wavelength Detector is virtually identical (someone plese correct me if I am wrong.

[Bruce Hamilton]

Page 240 of the 1100 series VWD manual has performance specifications. It lists bandwidth specification as "6.5 nm typical".

Bruce Hamilton