To determine sizes of plankton and particles imaged by the Imaging FlowCytobot (IFCB), one needs to convert pixels to units of length.
At the OOI Facilities Board IFCB Focus Group meeting in June 2025, data exercises used the following conversion factor for OOI’s IFCB images:
2.77 pixels per micrometer
This factor is appropriate in practice for recent IFCB serial numbers (note older IFCBs may have different conversion factor).
The McLane IFCB Datasheet (version 12/22) says “∼ 2.7 pixels/micron” because the precise factor should be determined for each instrument.
To confirm the factor 2.77 for OOI’s serial numbers 199, 200, and 206, we recommend evaluating several beads runs. The beads are Invitrogen “AlignFlow Plus 6 um” with actual size 5.6 um.