| 摘要 |
<p>This application discloses apparatus for logging the operation of a valve (10) of the type having a spindle (16) rotatable by a key (20) to effect opening and closing thereof, the apparatus including operative means (36) which are in use carried on a key (20), the operative means being operable independently of any other apparatus or electronic equipment to detect rotary motion of the key during operation of the valve. Preferably, the operative means includes sensor means (40, 42) sensitive to the earth's magnetic field, and is operative to determine rotation of the key by analysis of signals generated by the sensor means. By detecting valve operation with operative means on a key, the expense of providing detection apparatus for each valve is avoided (the total number of keys being much less than the total number of valves), as is the need to provide potentially delicate equipment in the hostile environs of the valves.</p> |
