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一、问题的提出采用接触式测量介质温度的温度表,都不会在瞬间即感应出介质温度。它们之间要经历一个热量交换过程。这一过程可用方程表达。设dQ为温度表在时间dr内对介质释放的热量(当介质温度低于温度表温度时),则 dQ=-hs(t-θ) dτ (1)式中,h——热交换系数;s——进行热交换的温度表的表面积;t——温度表的温度;θ——介质温度。在热交换过程中,温度表的温度变化程度dt取决于温度表放热而损失的热量dQ,即: dQ=mcdt (2)式中,mc为温度表感温球的热容量。
First, the issue of the proposed use of contact temperature measurement of the thermometer, are not in a moment that is induced by the medium temperature. Between them to go through a heat exchange process. This process can be expressed using equations. Let dQ be the heat released by the thermometer to the medium within the time dr (when the medium temperature is lower than the temperature of the thermometer), then dQ = -hs (t-θ) dτ (1) where h is the heat exchange coefficient, s - the surface area of the thermometer for heat exchange; t - the temperature of the thermometer; θ - the medium temperature. In the process of heat exchange, the temperature change of the thermometer depends on the amount of heat lost by the thermometer, dQ = mcdt (2) where mc is the thermal capacity of the thermometer.