We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
t
\
\
\
\N
\
S^
•x
"\
-5C
pm
26
Gpm
D 5 10 15 20
Fig. 18. Time factor (turbulent washing time compared to flowing water tank washing time) as a function of washing time; temp., 68 F; 1 X f channel at
26 gpm (R<f>*/D = 1.86 X 105); 1 X -^2 channel at 5 gpm (R<P*/D — 5.95 X
105).
Washing Time (Minutes)
time factor of turbulent fixing over no agitation fixing varies from approximately 2.55 to 3.75 (average 3.15). Similarly, the time factor of turbulent fixing over constant agitation fixing varies from 1.78 to 2.35 (average 2.06). It is interesting to note that the curve shown in Fig. 17 rises rather steeply initially, but levels off after an Re°*/D factor of approximately 105 has been reached.
Turbulent Washing. The data obtained from the experiments with turbulent washing are shown in Fig. 18. The time factor of turbulent washing over normal tank washing is defined as the ratio of the washing times between turbulent washing and the washing obtained by putting a sample in a tank through which fresh water is streaming at a moderate rate. The comparison is made when the two samples, both of which have been developed and fixed in the same manner, produce a precipitate of silver nitrate of the same quantity after washing. Two curves are shown in Fig. 18, one for a volume flow of 26 gpm with a 1 X f in. channel and one for a volume flow of 5 gpm for
a 1 X ^ in. channel. It can be seen that the last curve actually has the higher Re*-*/D factor and, therefore, rises above the other curve. It can be seen that the time factor varies approximately between 5 and 2 for the first curve and approximately between 5 and 2\ for the second curve.
Discussion of Results Obtained
Examination of Figs. 16 to 18 inclusive indicates that the speed of photographic processing can be adequately represented as a function of Re°-*/D under conditions of turbulent flow. Although it is important that the operation be performed at high Reynolds numbers such that the flow is turbulent, it can be noted that high Reynolds numbers alone are not sufficient to obtain rapid processing. Rapid processing will, however, be obtained at high values of Re**/D. The relationship of developing time and the Re°-*/D factor is in agreement with the theory except that the theory predicts a linear relationship between processing time and Re°-*/D. From the data obtained far it appears that the time factor is an approximate function of (R
126
February 1953 Journal of the SMPTE Vol. 60