| 摘要 |
<p>A flowmeter comprising a thermocouple and a current source for causing a temperature difference between the two junctions (24, 25) of the thermocouple. The thermocouple is connected to the current source (37) through a switch (36), a control input on the switch (36) being connected to a control device (35), also controlling a measuring circuit (34), which on its input port receives a signal representing the e.m.f. of the thermocouple (24, 25) during the periods of time where the current from the current source (37) to the thermocouple (24, 25) has been interrupted by the switch (36). The current source (37) and the hot and the cold junction of said thermocouple (24, 25) all are connectable in series by the control device (35) through the same two conductors (21, 22) also connected to the measuring circuit (33, 34).</p> |
