A high-sensitivity mode is available which lowers the detection threshold to 0.1 mm. With regards to counting and sizing, a laboratory OPC is functionally identical to the underwater version. The system connections are also similar, as shown in Figure 1.
Power is transferred from the deck unit to the remote unit via a two-conductor test cable.
The same conductors transmit frequency modulated data back to the deck unit, where readings are translated into standard RS-232 format and sent to a PC for display and storage. Water can be pumped through the OPC-1L in a variety of ways for processing live or preserved samples. Hoses may be attached to the laboratory unit's flow tube and run to pumps, circulators, or other devices. A target passing through the parallel optical beam blocks an amount of light proportional to its cross-sectional area within the beam. The linear detector then generates a pulse signal whose peak is amplified, digitized, and transmitted to the deck unit.