1. The Controller which provides Display, Control, Analog-to-Digital conversion and some of the signal processing. Initially it used a StampIISx, which was changed in 2009 to a Picaxe 40X2 in order to get increased ADC precision. This involved a new digital board, and the box wiring was cleaned up, but the analog board was unchanged.
2. For this project a new unit, the Battery Box, was constructed, which mounts under the System Unit, to which it is connected by a 15-conductor cable. This Battery Box includes a recording facility on a Secure Digital module, in addition to the rechargeable battery which can run the project for a day. Also provided are two additional analog inputs and a serial digital input.
3. The Probe is an accessory which plugs into the rear of the System Unit. It provides a bipolar voltage input and a bipolar, differential, current input. Separately, there are connections for a SPDT relay and a MOSET power switch.
