Hi Steve,

First you should understand that the question of field servicability is an issue that will be addressed at the applied engineering level. All I want to do is demonstrate that a functioning prototype can be built. At that point I will sell it to someone who has engineers on staff to implement a production design.

That being said, I have already taken some production considerations into account. For example, in the last benchtop version that I built, the electrodes were stamped instead of machined. So instead of paying a machinist to produce the electrodes, a press operator will be able to punch them out by the dozen.

As for the electronics, I'm not going to divulge any proprietary information but I can tell you that if I did this with analog circuitry there would be two deliterious points. First, it would increase the mass of the system dramatically. Second, no matter how much analog circuitry I added, it would represent a fundamental limitation on the system's performance (I know that's cryptic, but you'll just have to take my word that it's true). The net result is that it would be simply unfeasible to get down to <ppt sensitivity. By using a µ-controller I virtually remove that limitation, and I control the whole system with a single circuit board.

BTW Erik, the system I built in graduate school had a maximum voltage of 8kV_p-p (4 kV _0-p), which gave it a mass range of about 400 Da. And yes, getting too close is a mistake that you won't make twice (referring to your shocking experience).