| 摘要 |
<p>A gas meter (11) has a rotational indicator viewed by a photo-switch (30). Air is passed by a highly accurate bell prover along gasways (27) and through the meter. A test, automatically conducted by a controller, comprises comparing the volume measured by the bell prover with the nominal value of a complete rotation of the meter's indicator as signalled by the photo-switch. The controller has a print-out section which shows whether the meter is within a predetermined accuracy range, and if not, what correction is required.</p> |
