| 摘要 |
<p>A vacuum gauge of the ionisation type having a gauge head which comprises: an outer cathode sleeve having an inlet at one end for communication with the vacuum an anode positioned within the cathode sleeve and extending substantially co-axially therewith a guard ring interposed between the cathode sleeve and the anode positioning means at an end of the cathode sleeve remote from the inlet for positioning the cathode sleeve, the anode and the guard ring in predetermined spatial relationship with one another and in electrical isolation from one another wherein the positioning means and the guard ring are arranged substantially concentrically within the cathode sleeve. <IMAGE></p> |
