Description of SES Fluorometer Data Fields
P. McGill
v1.0.0, 11Dec23

The fluorometer measures fluorescence by exciting the target with 470 nm (blue) light, and
then measuring the light emitted by the target at 690 nm (red), and 590 nm (yellow-orange) to detect
chlorophyll a and phycoerythrin respectively.

Integration Time
All of the measurements are preceded by an integration time (e.g. "Dark Ref Integration Time"),
which is the length of time in milliseconds that the fluorometer integrates photomultiplier
counts for that particular measurement.

"Dark Ref 690 Counts" and "Dark Ref 590 Counts"
Before we move the carousel to place the sample plate beneath the fluorometer, we measure
the photomultiplier counts looking at the top surface of the bottom carousel plate with the
blue light off. This is a measurement of the fluorometer response with no excitation light
source and no fluorescent target material.

"Measure Ref 690 Counts" and "Measure Ref 590 Counts"
Before we move the carousel to place the sample plate beneath the fluorometer, we measure
the photomultiplier counts looking at the top surface of the bottom carousel plate with the
blue light on. This is a measurement of the fluorometer response with the excitation light
source on and no fluorescent target material. Some signal from the excitation light source
will get through the fluorometer's long-pass filters.

"Luminescence 690 Counts" and "Luminescence 590 Counts"
This is a measurement of light coming from the sample plate before we turn on the excitation light
source.

"Fluorescence 690 Counts" and "Fluorescence 590 Counts"
This is a measurement of fluorescence of the sample plate while the excitation light source
is on.

"Phosphorescence 690 Counts" and "Phosphorescence 590 Counts"
This is a measurement of light from the sample plate right after the excitation light source
is turned off.

"Constant Target Fluorescence 690 Counts" and "Constant Target Fluorescence 590 Counts"
This is a measurement of a puck of fluorescent plastic embedded into the top surface of the
bottom carousel plate. The reading from this reference target should be pretty constant.