| 摘要 |
<p>1466615 Preparing gas dilutions for analysis DRESSER INDUSTRIES Inc 9 Sept 1974 [16 Nov 1973] 39267/74 Heading G1B Apparatus for analyzing a sample gas which may be diluted in predetermined proportion with a diluting gas comprises a measuring device 10 for determining at least one characteristic of the sample gas; first, second, third and fourth flow control valves such as needle valves 35, 37, 36, 38 for providing respective first, second, third and fourth flow-rates with the ratio of the first flowrate to the second flow-rate being different from the ratio of the third flow-rate to the fourth flowrate to provide ultimately two different dilutions of the sample gas with the diluting gas; a first valve 18 for directing the sample gas from line 11 to the first flow control means 35 and a diluting gas from 16, 17 to the second flow control means 37 in a first position Fig. 3 (not shown) and for directing the sample gas from line 11 to the third flow control means 36 and the diluting gas from 16, 17 to the fourth flow control means 38 in a second position, which is the position shown in the figure, means allowing mixing of sample gas from the first flow control means 35 with diluting gas from the second flow control means 37 and directing the mixture towards the measuring device and of sample gas from the third flow control means 36 with diluting gas from the fourth flow control means 38 and directing the mixture towards the measuring device, and a second valve 13 for directing sample gas from line 11 directly to the measuring device 10 in a first position Fig. 1 (not shown) for measurement on undiluted sample, and for directing the sample gas to the first valve 18 in a second position Fig. 3 (not shown) for measurement on diluted samples. Operation of valves 13, 18 is by means of an airstream from source 20 directed by manually operated selector valve 21 to valves 13, 18.</p> |
