The Model 1211 Current Preamplifier was designed to provide all of the features 
required of a modern laboratory preamplifier. It measures current with full scale 
sensitivity ranging from 10-2 to 10-12
amperes. With a dynamic range of 96dB and 
output stability better than 0.003% per o C or per day plus a gain stability of 0.05% 
per o C of per day, its performance is unexcelled.

The classic analog design provides a clean signal without the high frequency “hash” 
encountered with microprocessor based designs employing multiplexed front panes 
displays. The wide gain bandwidth product permits calibrated, front panel rise time 
settings from 10?sec to 1 second.
The 1211 has a 600? output, a 50? output and a zero ? unity gain (converter) 
output. It may be gated off and on by a TTL Level Pulse at a rear panel connector at 
a rate up to 5 kHz for input overload suppression, etc.
Other convenience features include a 0-5 volt adjustable detector bias supply with 
100ppm per o C stability and calibrated current suppression of 10-3 to 10-10
amperes in 8 ranges.
The unit may be battery operated with the addition of the Option 10 Battery Pack. 
This allows the unit to run on batteries only, line power only, or while recharging 
from the line. Fast charge and trickle charge rates are switch selectable. External 
battery modification option M104 is also available so customer may use their own 
DC power supply to power the unit.