| 摘要 |
<p>A drive system for a pump/compressor which feeds a pneumatic circuit of a portable waste water sampling device, and comprising a plurality of individual electric motors (20) each operating at 12 volts and drawing a current no greater than 350mA at 2.5w, the motors driving a common pinion (23) with an output shaft (24) for connection to the pump/compressor. The use of a number of low capacity drive motors which together provide sufficient torque to drive the pump/compressor, avoids the danger of spark generation particularly in a potentially explosive environment such as may be found below ground. Since the motors are small they may be mounted conveniently within the sampling equipment, taking up no more space that would be occupied by a single motor of larger capacity.</p> |
