Acquire Spectra (G7121B Only)

Acquire Spectra (G7121B ONLY)

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 range and Step.

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

Scan Range: These two fields define the wavelength range for spectral storage.

Limits (Ex and Em): 200 – 1200 nm in steps of 1 nm.

Step: Step defines the wavelength resolution for spectral storage.

Limits: 1 – 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 – 1000 LU.

Acquisition time/rate

The acquisition time (in ms) for a single spectrum under the specified conditions is calculated and displayed.

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 LU step 10 — Resulting spectra will have 300 – 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 upper wavelength is adjusted according to the chosen step width.

Example: Em: 350 nm, Ex: 300 – 400 nm step 10 — Resulting spectra will have 300 – 320 nm

Data rate

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