Amplifier Whose Amplification Is the Exponential of an External Parameter

A method is described to achieve the current amplification of an amplifier equal to e
^x
, x being the angle of rotation of an axis. The systematic error is lower than 1 percent for |x| < 0.5. This device, used for the analog recording of the neutron monitor
¹
counting rate, solves the equation N(p
o
) = N(p)??e
^x
.