What do I gain by using the PreAmp remote mounting option?

Remote PreAmp mounting helps minimize the low-current noise in the measurements by reducing the length of cable that the un-amplified signal has to travel. Depending on the conditions of the test environment, the remote PreAmp mounting may start playing role when measuring currents from single pA (picoamperes) down to tens of fA (femtoamperes).

To mount PreAmps remotely, power down the 4200-SCS, remove the PreAmp guard, then remove the PreAmp(s) from the rear of the unit, and place them close to the test fixture or on top of the prober platten. You may want to use an (optional) accessory such as 4200-MAG-BASE, or 4200-VAC-BASE, or 4200-TMB to mount the PreAmps securely on the prober. Then re-connect the PreAmps to their respective SMUs using supplied remote PreAmp cables.