| 摘要 |
1,187,417. Separating gases by diffusion. VARIAN ASSOCIATES. 27 March, 1968 [27 March, 1967], No. 14805/68. Addition to 1109160. Heading B1L. In a gas sampling arrangement as described in Specification 1,109,160, and in which two similar membranes are used in series in the gas line to the mass spectrometer, the space between the two membranes is partially evacuated using a vacuum pump, a valve being connected in the line to the pump, so as to provide a control over the quantity of gases passing to the analyser. In this way the ratio of gases to be analysed passing to the mass spectrometer to carrier gas present in the gas flow from the chromatograph can be varied so that large peaks on the chromatograph output can be effectively reduced by cutting down the ratio of gases to analysed passing to the spectrometer so avoiding swamping of the spectrometer which may hinder subsequent analysis, whilst also allowing the detection of smaller peaks from the chromatograph. The valve is manually operated in accordance with the chromatograph output and comprises a magnetically displaceable valve member. |
