an 10 kohms standard resistor esi sr104 electro scientific industries portland oregon usa. one of the most stable resistors worldwide. used to calibrate special test equipment and precision dmm. remarkable, extremly low temperature coefficient of -0.01 ppm/°c and -0.03 ppm/(°c)². ageing about 1 ppm/year. for a 10 kohm value means this only 0.01 ohms/year. this device has 10000.23 ohms at 23°c. the ageing of this device is better than specified, last years could be measured almost not any drift. the resistor were never used under high currents, is stored always on the same place in an precise temperature and humidity controlled labority.
其中alpha=-0.01ppm/°c是一次斜率系数,beta=-0.03 ppm/(°c)²是2次斜率系数,也就是说,电阻=10000.23 * (1 + alpha * (t-23) + beta * (t-23)^2)
我的那个10k的年稳指标是10ppm,曲线和两个系数都没给呀,相反,国产的的年稳定的20ppm的反而有alpha和beta,分别是1.0ppm/c和-0.55ppm/c,差了不少啊。