SRS Preamplifiers

sr555Model SR555 Stand-On Scale Operating and Service Manual - SN 1800+ Part No. MAN555_060829 Page 13 of 18 CALIBRATION IMPORTANT CALIBRATION CHECKThe SR554 is a low-noise, transformer-coupled preamplifier optimized for source impedances between 0.05 Ω and 1 kΩ. With an input noise of only 0.1 nV√Hz, the SR554 can be used in a