| 摘要 |
<p>The heating period is controlled as a function of measurement of a suitable property of the melt. Specific options for the property monitored include a) vol., by response of a microswitch or displacement transducer to material dilation in a small borehole drilled radially into the wall of the pipe or fitting; (b) temp. measured locally within a borehole, or remotely by an irradiation thermometer or by disruption of a fusible link integrated with internal heater windings; (c) surfaces, monitored by a penetrometer needle.</p> |
