The TruIDL (Immersible Data Logger) measures voltage over the surface of the ware as it moves through the tank in an E-coat paint system. Voltage is directly related to the amount of E-coat paint film that has formed on the ware, and the TruIDL enables run-time data to be quickly analyzed. The TruIDL is battery powered and communications are handled by a Mini USB connection. An Excel based configuration file is transferred to the TruIDL, and the logs the E-coat process data. Once removed from the ware after the last rinse, the TruIDL's run data is transferred back to the same Excel file for viewing.