Cruise G g O ' 



Station 



£■0. /I 



SHF 



J .-78 



Total Larvae 



Anchovy L 



Sardine L. J. mackerel Pac. mackerel Hake Sebastodes Anchovy E. Sardine E 





Saury E. 



j:i 



;Tr 



qr^ 



03I 



foi 



t ?•? 



"■<■' ■ •^«v^4«>.,,.t (i) 2.99 





Fi^re 32. — Identifier's tabulation sheet with the same identifications as those listed in Figure 30. Here, how- 

 ever, code numbers for the identifications (see Fig. 31) have been written in for keypunching and automatic 

 data processing. 



CALIBRATION OF FLOWMETERS 



For calibration, a meter (s) is hauled or pushed 

 at different speeds over a measured distance. 

 (Our personnel have developed a method for cal- 

 ibrating three meters at a time, fastening them 

 to a bracket under a board — Figs. 33 and 34 — 

 and pushing them over the measured distance 

 — 42 ft = 12.2 m.) Performance tests are made 

 before (Fig. 35) and after every cruise, and a 

 graph is constructed in which the independent 

 variable is the length of a column of water needed 

 to affect one revolution of the meter (meters per 

 revolution) at any given towing speed. The 

 graph (Fig. 36) applicable to a given cruise is 

 based on the average of two calibration trials. 

 The graph is curvilinear with the highest values 

 of m/rev associated with the lowest numbers of 



rev/sec because of friction at low speeds. The 

 curve flattens out with increase in speed and a 

 corresponding decrease in friction. 



With preparation by automatic data proces- 

 sing (ADP), the meter calibrations are key 

 punched and programmed to produce a regres- 

 sion line where meters per revolution are plotted 

 against seconds per revolution in order to lin- 

 earize the relationship over the range of values 

 obtained in all the plankton tows for which the 

 meter was used. 



Standardization of data for every station on 

 a cruise is begun with the preparation of four 

 "sets" (Fig. 37) as follows: 



Set I — to derive the SHF from the for- 



10 D _ 10 D 

 V - Rap 



mula S 



82 



