Journal of the Society of Motion Picture and Television Engineers (1950-1954)

of approximately 5 to 1 in the Re°-*/D factor produced a variation of approximately 2 to 1 in the time factor, either when compared to no agitation development or constant agitation development. It appears that the time factor is greater for higher gamma development than for lower gamma development. The lower ends of the curves in Figs. 12 and 13 are not shown but it can be noted that the curves in Fig. 12 should go through the point 1.0 on the ordinate when the abscissa (Re°-*/D) is 0. This indicates that when the fluids are at rest the time factor is 1. Similarly, the curves in Fig. 13 should go through 0.6 on the ordinate when the abscissa (Re^/D] is 0, indicating that the ratio between no agitation and constant agitation is approximately 0.6. In Figs. 14 and 15 are plotted the time factors as a function of gamma comparing turbulent developing to no agitation developing and constant agitation developing. It can be seen that the time factor, in general, increases slightly as the gamma increases and that this increase is not always constant. The dispersions in the curves must be attributed to the fact that insufficient data were taken, so that a small amount of fog or uneven developing would cause a considerable uncertainty in the data. Figure 15 gives a good indication of what type of data can be expected. All curves follow a fairly reasonable pattern in that the time factor increases as a function of Re°-*/D. The only exception in these curves is the second one from the top (marked with squares) which was taken with channel 7. This channel was completely different from all the other channels in that it had a width of 2 in. instead of 1 in. and its opening depended completely on the fluid pressure. It was observed that the development across the width of the channel was not even under all conditions and, therefore, considerable variation in data may have taken place. All the other curves follow a regular pattern except that some of them seem to indicate that the time factor vs. gamma curve is a linear curve, and the upper three indicate that the curve might be slightly concave with a minimum gamma of approximately 1.0. Insufficient data were taken to determine the exact behavior of the curves and consequently they were plotted as the experimental points indicated. It is interesting to note that the curves obtained with channel 6 (1 X -^ m-) at a Reynolds number of 38,700 and with 8.7 gpm of developer flowing through the chamber showed a time factor in excess of 2 over the entire range of gamma. The horsepower required for this rate of developing was approximately ^. Turbulent Fixing. The results of the turbulent fixing experiments are shown in Figs. 16 and 17. It can be seen from these figures that the large number of results obtained with different channels follow a clearly definable pattern when plotted as a function of Re°*/D. From Fig. 16 it can be seen that the clearing time for no agitation fixing is 255 sec, the constant agitation clearing time is 158 sec, and the turbulent fixing time varies from 100 sec to 68 sec over a range of Re°-*/D from 0.4 to 8.8. A plot of the turbulent fixing time factors over no agitation fixing and constant agitation is shown in Fig. 17. The time factors as shown in Fig. 17 are defined as follows: 1 . The time factor of turbulent fixing over no agitation fixing is defined as the ratio of the fixing times between turbulent fixing and no agitation fixing to reach the same clearing point (total clearing). 2. The time factor of turbulent fixing over continuous agitation fixing is defined as the ratio of the fixing times between turbulent fixing and continuous agitation fixing to reach total clearing. It can be seen from Fig. 17 that the 124 February 1953 Journal of the SMPTE Vol. 60