| 1. | Digital lock - in amplifier based on dsp and sampling adc
的数字锁定放大器 |
| 2. | Lock - in amplifiers
锁定放大器 |
| 3. | A computer controls the whole process of measurements by communicating with the lock - in amplifier via rs232 interface
计算机通过rs232接口与锁相放大器通信，控制测量的全过程。 |
| 4. | A lock - in amplifier is used to supply the driving signal and to detect the output signal corresponding to the sample ' s strain
使用锁相放大器提供驱动信号，并同时检测对应于样品形变的输出信号。 |
| 5. | Photoelectric detecting circuit is constituted of four parts , i / v conversion , lock - in amplifier , low - pass filter and operation
光电检测电路由四部分组成,分别是i / v转换环节、锁相放大环节、低通滤波环节、运算环节。 |
| 6. | The core of the lock - in amplifier used to measure response of laps consists of a high precision modulator / demodulator and dds as signal generator
对于光寻址电位传感器，我们设计了以高精度调制解调器件和数字频率合成器件为核心的模拟锁相放大器。 |
| 7. | For the signals are very weak , the lock - in amplifier is employed to extract the signals in the circuit design . it can inhabit the noise in the most and maximize the signal - to - noise
因为信号十分微弱，所以在电路设计上采用锁相放大器来提取信号，最大限度的抑制噪声，提高系统的信噪比。 |
| 8. | Using the home made device , the relationship between the 3 voltage and the heating frequency is obtained by lock - in amplifier , thus the thermal conductivity of the fluid is calculated with the least square fit method
自行研制了流体导热系数的测量装置，采用锁相放大器获取3电压与频率的关系，并借助最小二乘法，算出待测试样的导热系数。 |
| 9. | The experiment results show that : the frequency stabilization of the optimized doppler modulator has already reached rms error about 1 % , which could meet the need of reference signal of the lock - in amplifier
实验结果表明，经过优化后的多普勒调制器的输出调制信号频率的相对标准误差达到了1 %左右，能够满足锁相放大器对输入参考信号频率稳定度的要求。 |
| 10. | Choosing y type reflection fiber optic detector , this thesis create a tiny displacement - detecting sensor that is made up of led ( light emitting diode ) , fiber optic detector , electric eye , lock - in amplifier , display and other electro circuits
本论文采用y型反射式光纤探头设计制作了一种微位移测量装置，它主要由发光二极管、光纤探头、 、锁相放大器、显示器及相关电路组成。 |
