摘要
比较了在光磁共振实验中不加射频场、固定射频场、改变射频场3类测量地磁场水平分量的实验方法.提出利用反向测量、线性拟合等方法进行改进,一定程度上克服了原来实验方法的缺点.
A simple method to monitor infrasound is introduced as a combination of common condenser microphone and sound card. With high frequency carrier wave generated by sound card, harmonic infrasound wave can be measured with amplitude modulation technique. As for non-harmonic wave, its high frequency multiplication components are transferred into measurable signal. The sequential signal is converted to spectral distribution using Fourier analysis to acquire the frequency and strength of infrasound. Furthermore, based on virtual instrument technique and network hardware, the environmental infrasound can be explored with Web/Browser technology primarily.
出处
《物理实验》
北大核心
2010年第10期43-46,共4页
Physics Experimentation
关键词
光抽运
磁共振
地磁场
infrasound monitor
capacitance microphone
amplitude modulation
virtual instrument
