针对传统光照功率计采用积分法测量功率引起的高误差, 从应用角度出发, 提出一种MSP430为主控制器的高精度光照功率计。光电传感器将光信号转换为毫安级电流信号, 经过负反馈电流放大转换电路, 再通过差分放大和滤波电路, 经过24位高精度AD模数转换芯片将模拟信号转为数字信号, 再融合递推和中位值数字滤波算法, 计算得到光照功率。通过LCD实时显示测量值, 并经过Savitzky-Golay滤波器后显示随时间变化的测量曲线。实验证明, 所设计的光照功率计误差低于0.3%, 具有功耗低、系统稳定、显示界面友好的优点, 可以存储测量数据, 显示光功率曲线。

Aiming at the high error caused by the integral method for the traditional optical power meter, from the application point of view, a high-precision optical power meter with MSP430 is proposed. The photoelectric sensor converts the light signal into mA current signal, through a negative feedback current amplification, and then through a differential amplification and filtering circuit, and converts anolog signal into a digital signal through a 24-bit high-precision AD chip. The optical power is calculated using recursive and median digital filter. The measured value is displayed on the LCD. The optical power curve is also displayed after through the Savitzky-Golay filter in measurement phase. The experiment proves that the optical power meter has an error of less than 0.3%, low power consumption, stable system, friendly display interface, it can store measurement data and display optical power curve.