A camera and image-analysis system for in situ observation of flocs in natural waters
Eisma, D.; Schuhmacher, T.; Boekel, H.; van Heerwaarden, J.; Franken, H.; Laan, M.; Vaars, A.; Eijgenraam, F.; Kalf, J. (1990). A camera and image-analysis system for in situ observation of flocs in natural waters. Neth. J. Sea Res. 27(1): 43-56 In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579; e-ISSN 1873-1406, more | |
Authors | | Top | - Eisma, D., more
- Schuhmacher, T.
- Boekel, H.
| - van Heerwaarden, J.
- Franken, H.
- Laan, M.
| - Vaars, A.
- Eijgenraam, F.
- Kalf, J.
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Abstract | An in situ suspension camera in combination with an image-analysis system was developed at NIOZ to measure the in situ particle size of suspended matter. It differs from other methods in that in situ particle size is measured from ~ 4 µm upwards in a relatively simple and direct way. It can be used in any waters down to ~ 4000 m depth (with some adjustments to 7000 m) and in water with a suspended matter concentration up to 200 mg·dm -3. In very clear ocean water the system becomes inconvenjent because of the large number of photographs that have to be taken to obtain a reliable size distribution. This paper describes the camera and the image-analysis system and gives some results of measurements in the Scheldt river and estuary in April 1989. These measurements show a continuous size distribution by volume between 3.6 µm and 644 µm and a good agreement of the data obtained with the 1:1 and 1:10 cameras. |
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