A modular form factor power module system with monitoring and control functions is disclosed. A humidity-controlled controlled chamber incorporates a housing, a humidifier, a sample chamber, a reference chamber, Peltier devices, humidity and temperature sensors, and gas transmission lines into a single unit. The edge drilling is done with an attachment for the proper size bit or with a \xbc inch pilot hole and hole saw. The base assembly comprises a stirbar and a supporting disk which contains a ceramic magnet. In another exemplary embodiment, the electrode catheter determines the contact and coupling condition based at least in part on a phase angle of the impedance.