Why is the pass/fail criterion for wavelength accuracy qualification on the fluorescence detector ±6 nm? - WKB236967

ENVIRONMENT

• Empower
• System SQT

ANSWER

• To start with, it is important to note that the light in a fluorescence detector passes through two monochrometers before being detected.
• Wavelength accuracy of the Waters ACQUITY FLR emission monochrometer is ±2 nm.
• Wavelength accuracy of the Waters ACQUITY FLR excitation monochrometer is ±2 nm.
• This means that the tolerance with respect to total wavelength accuracy is increased by at least the square root of 2 times the tolerance of each individual monochrometer, so this value is rounded to a combined specification of ±3 nm.
• For the qualification tests employed by the SystemsQT, a second-order reflection is used, so the wavelength tolerance of the second-order output must be doubled to ±6 nm.
• This is why the qualification pass/fail criterion is listed as ±6 nm.

ADDITIONAL INFORMATION