Stanford Research Systems SIM918 Operating And Service Manual page 6

iv
Caution regarding use with photomultipliers
CAUTION
Service
Preparation for use
to large input currents. Therefore, Stanford Research Systems does
not recommend the SIM918 for such applications.
The front-end amplifier of this instrument is easily damaged if a
photomultiplier is used improperly with the preamplifier. When left
completely unterminated, a cable connected to a PMT can charge
to several hundred volts in a relatively short time. If this cable is
connected to the curent input of the SIM918, the stored charge may
damage the front-end JFET. To avoid this problem, provide a leakage
path of about 100 k to ground inside the base of the PMT to prevent
charge accumulation.
Do not install substitute parts or perform unauthorized modifications
to this instrument.
The SIM918 is a single-wide module designed to be used inside the
SIM900 Mainframe. Do not turn on the power to the mainframe or
apply voltage or current inputs to the module until the module is
completely inserted into the mainframe and locked in place.
General Information
SIM918 Precision Current Preamplifier