Acquire Spectra (Modular LC FLD)

Acquire Spectra is available only if the application supports it. It is not available with the G1321C or G7121A FLDs.

If you choose multiple excitation or emission wavelengths, you can also choose to acquire spectra:

None

No spectra are taken.

Apex

A spectrum is acquired at the apex of the peak.

All in Peak

All spectra within the peak are acquired.

All w/o signal

All flashes are used for spectra acquisition. The mean value of all measured wavelengths is shown on channel A. This setting is useful for unknown spectra. Spectra are acquired continuously depending on the settings of the the range and Step.

If there are no peaks in Signal A, there are no spectra.

Scan Range .. to	These two fields define the wavelength range for spectral storage. Limits (Ex and Em): 200 to 1200 nm in steps of 1 nm.
Step	Step defines the wavelength resolution for spectral storage. Limits: 1 to 20 nm in steps of 1 nm.
Threshold	The Threshold is the height in LU (Luminescence Units) of the smallest expected peak. The peak detector ignores any peaks that are lower than the threshold value and does not save spectra. Limits: 0.001 to 100 LU in steps of 1 LU. The acquisition time (in ms) for a single spectrum under the specified conditions is calculated and displayed. The acquisition rate depends on: the number of additional signals specified the scan range of spectral acquisition the step size (wavelength resolution)

Fit Spectral Range

Select Fit Spectral Range to adjust the spectral range so that there is always a difference of at least 25 nm between the excitation wavelength and emission wavelength. This ensures that no first order stray light is measured due to the excitation and emission wavelengths being too close. If the range of the emission spectra overlaps with the excitation wavelength, first order stray light adds spectral bands in the emission spectra. Multi Emission The lower emission wavelength of the resulting spectra is set to be at least 25 nm higher than the excitation wavelength. The upper wavelength is adjusted according to the chosen step width. Example: Ex: 280 nm, Em: 300 - 400 nm step 10 — Resulting spectra will have 305 - 395 nm Multi Excitation The upper excitation wavelength of the resulting spectra is set to be at least 25 nm lower than the emission wavelength. The lower wavelength is adjusted according to the chosen step width. Example: Em: 350 nm, Ex: 300 - 400 nm nm step 10 — Resulting spectra will have 300 - 320 nm

Data rate

The data rate is calculated according to the specified scan conditions.