通过恰当控制入射光强度来准确测量普朗克常量

Accurate Measurement of Planck Constant by Controlling Intensity of Incident Light

为了消除因光电流曲线的变化率的差异对确定截止电压的影响,提出了通过恰当地控制入射光强度,使不同频率的光电流曲线的变化率相同;为了消除光电流曲线的起始位置和线性部分的倾斜程度不同对确定截止电压的影响,提出了采用"平行等距法"确定截止电压;为了抑制漂移对测量的影响,提出了适当降低仪器的灵敏度,提高仪器稳定性的测量原则.实验结果表明:采取这些措施,测量普朗克常量相对误差由2.5%可降到0.7%.

In order to eliminate the influence of differences from rate of change in photocurrent curve on cutoff voltage, the rate of change in photocurrent curve with different frequencies remains the same by proper controlling of incident intensity. ＂Parallel isometry method＂ is put forward to obtain cutoff voltage so as to eliminate the influences on cutoff voltage from changing of initial position and inclination of photocurrent curve. The measurement principle of appropriately reducing sensitivity and accordingly improving stability of instrument proposed to restrain the effect of wander on measurement. The result indicated that the relative error of Planck constant decreased from 2.5% to 0.7% by measures.