| 摘要 |
<p>1258002 Measuring temperature difference and quantity of heat SVENSK VARMEMATNING CB-SYSTEM AB 26 Feb 1969 [27 Feb 1968] 10395/69 Headings G4D D6Y D6C1 D6C2 and D7X A frequency signal derived in a converter 3, Fig. I from a current representing the temperature difference between two elements 1, 2 is fed via a gate 4 enabled for constant time intervals to a counter 5. The gate 4 may be controlled either by a source 9 generating a fixed number of constant duration impulses so that the count represents the temperature difference or, if the temperature difference is between two points in a flowing medium, by a fluid-flow meter 8 delivering pulses for each increment of fluid passing through the meter so that the count represents the quantity of heat used. The apparatus may be used to measure the quantity of energy consumed in a given time above a predetermined threshold by accumulating pulses above the threshold level received during the given time in a further counter 11. In the embodiment of Fig. 3 (not shown), a pulse oscillator (24) delivers a frequency signal proportional to the predetermined level to the forward input of a counter (25) for a time T, a gate (4) being enabled at the next pulse from the flowmeter (8) so that the counter (25) is decremented by a number of pulses representing the temperature difference. When the counter (25) reaches 0 a gate (26) is enabled so that succeeding pulses, i.e. excess pulses, are accumulated in a further counter (27). The temperature sensitive resistances 1, 2 are connected to identical secondary windings 13, 14 of a mains connected transformer 12, the current summed at the collector junction of transistors 17, 22 in series with the elements 1, 2 being proportional to U x temperature difference where U is the voltage derived from the windings 13, 14. By connecting a further identical secondary winding 15 to a converter 3, the frequency output of the latter is proportional to the temperature difference.</p> |
