Keywords : fluorometer


The fluorometer is a permanently installed device aboard Thalassa.

Instrument used: TURNER 10-AU-005-CE

The fluorometer is connected onto the same sea water circuit as the thermosalinometer and measures the concentration of chlorphyll present in the sea water. The phytoplancton cells are lit by a beam of ultraviolet light. Their chlorophyll content absorbs the light which is then re-emitted in infrared. The phytoplancton density can be determined in this way.

Technical specifications of the instrument:

Sensitivity: 30 parts per trillion of extracted chlorophyll a.
Dual beam optics: compensate for drift in intensity of the low pressure mercury vapour lamp (4 watts; 8,000 hours lamp life) and/or photomultiplier drift.

Automatic range selection: manual or automatic range changing in response to different concentration levels (user selectable).

Ranges: 3 ranges, each a factor of 10 more sensitive than the next from 0 to 9999,999 florescence signal units.

Blanks: reads and subtracts blanks (user can select manual or automatic blank correction).

Digital output: 100% ASCII format through an RS-232 serial cable

Analog output: full scale voltage: 0,1, 1, 2 or 5 volts (user selectable).

Readout: direct concentration or raw fluorescence.