The output from many detectors is a current (some number of electrons / second). It is desirable to convert this current signal to a voltage to avoid capacitive charging effects. The simplest way to do so is to drop the current across a load resistor and measure the voltage.
Schematic of a I to V conversion using a resistor:
This simple current-to-voltage converter has some disadvantages that can be avoided by using an op-amp.
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Copyright © 1996 by Brian M. Tissue