这里简短地叙述一种气相色谱用的热导检测器。这种检测器中的灵敏元件不是通常所用的热丝或热敏电阻,而是采用晶体三极管。当供给晶体管的电功率与被流经晶体管的载气带走的热量相当时,晶体管的温度θ_E 是恒定的。当载气中有从色谱柱中分离出来的样品组分时,由于混合气体与纯载气的热导率不同,致使灵敏元件温度改变△θ_E。此温度变化通过电桥转变成电信号输出。 Here is a brief description of a gas chromatography with thermal conductivity detector. Instead of the usual hot wire or thermistor, the sensor in this detector uses a transistor. The transistor temperature θ_E is constant when the electrical power supplied to the transistor corresponds to the amount of heat removed by the carrier gas flowing through the transistor. When the sample component separated from the column is contained in the carrier gas, the temperature of the sensitive element changes by Δθ_E due to the difference of the thermal conductivity between the mixed gas and the pure carrier gas. This temperature change through the bridge into electrical signals output.