THE HONGKONG GOVERNMENT GAZETTE, MARCH 16, 1906. 297
If a flash oceurs at any temperature between 76° and 150° Fahrenheit, the temperature at which it occurs subject to correction for atmospheric pressure, is the flashing point of the sample.
In repeating a test, a fresh sample of oil must always be used, the tested sample being thrown away, and the cup must be wiped dry from any adhering oil, and cooled, as already described, before receiving the fresh sample.
5. CORRECTION FOR ATMOSPHERIC PRESSURE.-As the fishing point of an oil is influenced by changes, in atmospheric pressure to an average extent of 1°6 Fahrenheit for every inch of the barometer, a correction of the observed flashing point may become necessary. The true height of the barometer must, therefore, be determined at the time of making the test for the flashing point. To facilitate the correction of a flashing point for pressure a table is appended, giving the flashing points of oils ranging from 65° to 80° Fahrenheit, under pressures ranging from 27 to 31 inches of merenry.
The table is used in the following manner :--
EXAMPLE. An oil has given a flashing point of 71°, the barometer being at 28-6; take the nearest number to 71° in the vertcial colummu headed 23-6. This number is 70-8. Substituto for this the number in the same horizontal line in the column headed 30 (the normal height of barometer). The Substituted number, i.c., the true flashing point of the oil, is 73°.
TABLE for correction of FLASHING POINTS indicated by the Test for Variation in Barometric Pressure on either side of Thirty Inches.
BAROMETER IN INCHES.
27 27.2 27.4 276 27·8 28 282 284 286 28.8 20 29-2 204: 296, 298 30
FLASHING POINTS IN DEGREES FAHRENHEIT.
302 304 30.6 30-8
31
60.2 60.5 60·8 | 61·2; 615 61.8 62.1 62.4: 62-8 | 631 · 634 612 615 61.8 62-2 62-562-8 631 634 63-8 61' 644 62.2 62·5 | 62·8 | 63-2 635 638 641 614 648¦ 651 | 654 657 632 635 63-8 642 645 648 65-1 654 65-8 66-1 64-466-7 642 645 648 65-2 655 65-8 66-1 664 66-8 671 674 677 652 655 65-8 66-2 665 66-8 671 674 67-8 681 684 66-2 665 66-8 672 675 67-8 68-1 684 68-8 69-1 694 672 675 67 8 682 685 688 691 694 698, 701 70-4 68.2 68.5 6-8 692 69-5 69-8
70-1 704 70-8 711 714 69-2 69.5 69-8 702 705 708 711 714 718 721 70-2 70-5 70-8 712 715 718 72 1 724 72-873-1 71-2 715 71-872-27255 728 73.1 734
744 72.2 72.5 72-878-2 735 738 741 | 744 748 751 7514 75'7 176 73.2 73.5 738 742 745 748 751 754 75-8 761 764 76-7 i 77 71.2 745 748 752❘ 75·5 75-876-1 76.4 76.8 771 774 777 75-2 755 75-8 76-2 | 765 | 768 | 771 77-4 77-8
63.7
64
647
65
644 647 65 654 65.7 66
65 3 65-6 66 66.3 663 66.6 67
66.0
673
67-6
66
66-4¦ 66-7
67
67-3 67.6 68
68-3
68 6
67
674 67-7
G8
68.3 68 6
69
69-3
69-6
68
684 687 69
69-3 69.6
70
703
70-6
68-7 697 70
69
69-4 69-7
70
70-3 70.6 71:
718
71-6
704 70-7
71
713 71-6
72
72.3 72.6
7071 71
714 71-7
72
72.3 72.6 73 733 73.6
71.7 72
72.4 72 7
73
73.3 73.6 74
7+3
74.6
724 72-7
73
73-4 73-7
74
743 74-6 75
75.3
75.6
734
73 7
74
744 74.7
75
75.3 756 76
76.3
76 6
78 8 741
747)
75
75-4 75.7
76
763 76-6 77
77·8
77.6
76-4 76-7
77
773 776 78
783 78.6
774 77.7
78
78.3 78.0 79
79-3 79.6
78
78-4 78-7
79
79-3. 79-6 80
80-3 80.6
78.1 784 787
79
794 79 7
80
80.3 80.6 81
813 816
COUNCIL CHAMBER,
15th March, 1906.
A. G. M. FLETCHER,
Clerk of Councils.
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