. Journal. posed ammonia. Themixture of nitrogen and hydrogen, free fromammonia, passes another differential manometer,Dj. a rotameter, R, and finally reaches a gasmet«r, G. A constant ciurent of ammonia ispassed through the system and so much electriccurrent supplied to the heating coUs of the copper inflow or outflow, which can, however, be accur-ately measured by passing an inert gas through thesystem. Measurement of temperature. As the accuracyof the results depends on the accuracy of themeasuiements of temperature, of energy, and ofgas volmne, these have to be carried out withsufficient p
. Journal. posed ammonia. Themixture of nitrogen and hydrogen, free fromammonia, passes another differential manometer,Dj. a rotameter, R, and finally reaches a gasmet«r, G. A constant ciurent of ammonia ispassed through the system and so much electriccurrent supplied to the heating coUs of the copper inflow or outflow, which can, however, be accur-ately measured by passing an inert gas through thesystem. Measurement of temperature. As the accuracyof the results depends on the accuracy of themeasuiements of temperature, of energy, and ofgas volmne, these have to be carried out withsufficient precautions. Owing to the lack of after-effect. Le Chateliers thermocouple was preferredto others, one junction being kept as usual incontact with the body of which the temperature wasto be measured, while the other junction was keptat 0 C. The thermo-electric power can bemeasured by a millivoltmeter or by a compensa-tion method, the temperatures thus found beingdifferent from each other. They may be called. Fio. 3. thermostat, the preheater, and the decomposer,that all three are kept at the same the ammonia enters the decomposer at aselected temperature and leaves it at the sametemperature after decomposition. The amount ofenergy supplied to the decomposer in order tocompensate the heat loss bj^ the decomposition,gives the heat of formation at that temperaturefor that amount of ammonia decomposed in thedecomposer. This is apparently only admissiblewhen there is neither heat gain from nor heat lossto the surroundings on the part of the temperature inequality of the decomposer withthe surroundings will naturally cause a certain heat uncompensated temperature and compensatedtemperature. The uncompensated temperatureis read usually by means of a millivoltmeter withhigh resistance, sometimes directly graduated in atemperature scale and called a pj-rometer. It isimpossible to get an accurate temperatiu-e recordby means of a pjTometer, since the instru
Size: 1513px × 1652px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectchemist, bookyear1882
