SRS,Stanford Research Systems,SR555,SR556,

sr555SR555 Current Preamplifier. 10 VµA gain; 120 kHz (-3 dB) bandwidth; SR556 Current Preamplifier. 5 fA√Hz input noise; 1 VnA gain; SR556 Current Preamplifier. 5 fA√Hz inputModel SR555 Stand-On Scale Operating and Service Manual - SN 1800+ Part No. MAN555_060829 Page 13 of 18 CALIBRATION IMPORTANT CALIBRATION CHECK