Improvements relating to the flame-photometric testing of flammable gases and apparatus therefor

摘要

PICT:0779212/III/1 In a known method of determining the constituents of a flammable gas in a line 1 the flow passes from line 4 to two branches 5, 6. Branch 5 feeds a measuring flame 33 while branch 6 is again split to branches 7 and 8 one of which is unaffected while the other passes through material 9 absorbing the constituent to be determined. The latter two streams are recombined in tube 10 and feed comparison flame 34. The intensity of these flames is compared by photo-cells 37, 38 potentiometer 39 and voltmeter 40. According to the invention the device 14 comprising a differential pressure-responsive diaphragm and valve 16 maintains the ratio of the flow in the branches 5 and 10 constant. Valves 56 and 60 enable the replacement of material 9 by material 58 as desired. Branches 12 and 13 contain "flow meters" and flow indicators 42, 43 and device 11 maintains the ratio of the flow in these two branches constant. In the modification described with reference to Fig. 2 (not shown) the flow in branch 10 is adjusted instead of that in branch 5.