Bio-Rad VersaFluor™ Fluorometer - Manual (Page 11)

Fig. 4.2. Optical system.
Emitted fluorescent light from the cuvette is focused by the spherical mirror and passes
through the first aspheric lens. The emission filter allows light specific to the fluorescent com-
pound to reach a second aspheric lens which directs the fluorescent light to the photodiode
detector. The detector system is a broad spectrum photodiode with analog circuitry to ampli-
fy the signal. The amplified analog signal is converted into a digital signal and processed by
the controlling microprocessor before being sent to the fluorescence units display. The num-
ber in the Fluorescence Units Display (Section 2.2) represents the relative fluorescent units
(RFU).
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PD detector Emission filter
Aspheric lens
Spherical mirror
Excitation filter
Quartz light
Cuvette