抄録
The υ-β diagrams which denote the relation between the vecuity and the dopth of the top or bottom end plate of full cans are able to be classified into four types according to the ex-hansting and sterilising processes as follows :
I. (a) With vacuum seamer and common retort.
II. (b) ?? ?? ?? ?? equi-pressure retort.
III. (a) With exhaust box and common retort.
IV. (b) ?? ?? ?? ?? equi-pressure retort.
The author reproduced the above four models of the υ-β diagrams of full cans experi-mentally with empty cans, two models I. (b) and II. (b) by the vacuum test, and the other two models I. (a) and II. (a) by the compound test which are described in detail in this paper.
The υ-β diagrams obtained experimentally as above mentioned were compared with the mean lines of measured vacuities and end plate depths of the test cans.
The test cans were prepared in three kinds, one in the empty can seamed with vacuum seamer but with no sterilization, another in the cans filled with water and processed with either exhaust box or vacuum seamer and sterilized in the common retort in usual way, and the other in the crab and salmon 11b. cans circulated in market. The bare cans as vessels were all manufactured by the same maker in 1935
The experimental υ-β line coinsides pretty well with the mean line through the observed points in each kind for the cans of crab-can form, but for the cans of salmon-can form the deviation of the experimental line from the latter becomes a little larger, therefore it is pre-ferable to take the latter as the calibration scale of the vacuity for the “Dial Vacuum In-dicator.”
The mean value of deviations of the observed points from their mean lineis smaller than 2 inches in vacuum for almost all cases, and taking the mean of the top and bottom end plate depths the mean value of the deviations of the observed paints from their meam line is reduced to only 1•5 inches in vacuum for all cases as shown in table 2.
