The SR550 Voltage Preamplifier is specifically designed to be used together with SRS lock-in amplifiers. These pre-amplifiers promote gain nearing to the experimental detector prior to the permanent degradation of signal-to-noise ratio through pickup and capacitance of the cable. This instrument minimizes connecting lines’ noise and pickup and also minimizes time of measurement in experiments with limited noise. The preamplifier gain is mechanically chosen when used with SR510/SR530 maximizing noise performance not compromising the dynamic reserve. As for SR810/SR830/SR850, the gain is mechanically set to the maximum. The SR550 can also be independently operated with the application of proper biasing from the lock-ins.sr550电压的前置放大器是专用来与SRS相放大器一使用。些前置放大器的增益接促实探测器的信噪比电缆的电容拾取和永久化之前。仪器将接线的噪声和干扰也最大度地减少噪声的实测与有的时。前置放大器的增益是机械择当使用sr510 SR530最大噪声性/不影响动态储备。于sr810 / SR830 / 850增益是机械置的最大。sr550的也可以与当的偏压的定应用程序独立。