. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. \Y. G. HAND, P. A. COLLAR!) AXI) I). DAVEXPORT 92 Tin- scan is transferred by a mirror to a type 1 P21 photomultiplier tube and associated preamplifier unit. Changes in light intensity within the scan, caused by objects (such as moving organisms) between the scan and the photomultiplier tube, are registered by that tube as changes in electrical potential. The potential change* are amplified and transmitted to a second Dumoiit 30411 oscilloscope mounted horizontally. This scope in turn displays a "negative" image of
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. \Y. G. HAND, P. A. COLLAR!) AXI) I). DAVEXPORT 92 Tin- scan is transferred by a mirror to a type 1 P21 photomultiplier tube and associated preamplifier unit. Changes in light intensity within the scan, caused by objects (such as moving organisms) between the scan and the photomultiplier tube, are registered by that tube as changes in electrical potential. The potential change* are amplified and transmitted to a second Dumoiit 30411 oscilloscope mounted horizontally. This scope in turn displays a "negative" image of the intensity dif- ferences in the generated scan, , the discrete areas of reduced illumination in the original scan are finally displayed as light "blips" on a dark field, each blip recording the organism's position at the moment it is scanned. Resolution of the system is fine enough for it to perceive relatively opaque organisms larger than 15-20 fj., and to distinguish the external morphological features of many forms in the 50-300 ^ range. By coupling a Dumoiit type 450A oscilloscope camera fitted. Fi<;ri<K 2. Pathways f (/«»vi<l\cdra. with a Kobot "Recorder 24" 35-mm. camera-back to the displav scope, track images of moving organism* may be photographically recorded as they occur; a time exposure on Kodak Tri X Pan film records the positional images or blips for a chosen number ol *can* ( fig. 2 ). \\ ith scan rate as well as power of magnification known, information necessarv for linear velocity determination is available. \\ c determine field magnification by photographing, at the beginning of each te*t MTJCS, a calibrated guide of known dimension; for this purpose a Incite slide inscribed with parallel line* 1 mm. apart was used. I hit a analysis Films of pathways were projected onto a 1 X M. rectangular wall-screen divided into nine equal sections, each of which was numbered. A table of random. Please note that these images are e
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
