| 摘要 |
<p>A dual piston/poppet valve in a fuel dispenser works with a two-stage valve to help eliminate errors from an inferential flow meter. When the two-stage valve opens partially, a secondary fuel path is opened in the dual piston/poppet valve. A sensor detects the opening of the secondary fuel path and reports its opening to a control system. The two-stage valve opens fully and a primary fuel path is opened concurrently, During transaction completion, the two-stage valve partially closes, resulting in the closing of the primary fuel path. When the two-stage valve closes completely, the secondary fuel path closes. The sensor detects the closing of the secondary fuel path and reports the closing to the control system. Based on the outputs of the sensor, the control system accepts or declines input from a flow meter.</p> |
