美国斯坦福SRS 射频锁相放大器SR844

25kHz—200MHz频率范围, 100s -30ks时间常数；6，12，18，24dB/倍频程衰减,

 内部或外部参考源；自动量程；存储和调用9个仪器设备, 标准GPIB，RS—232接口

The SR844 is the widest bandwidth lock-in amplifier available. It provides uncompromised performance with a frequency range of 25 kHz to 200 MHz and up to 80 dB of drift-free dynamic reserve. It includes the many features, ease of operation, and programmability that you've come to expect from SRS DSP lock-in amplifiers.

　　· 25 kHz to 200 MHz frequency range

　　· 80 dB dynamic reserve

　　· Time constants from 100 μs to 30 ks (6, 12, 18 or 24 dB/oct rolloff)

　　· "No Time Constant" mode (10 μs to 20 μs update rate)

　　· Auto-gain, -phase, -reserve and -offset

　　· Two 16-bit DACs and ADCs

　　· Internal or external reference

　　· GPIB and RS-232 interfaces