The instrument utilizes at least one electromagnetic signal transmitter and at least one electromagnetic signal receiver with the receiver detecting a receiver signal responsive to the transmitter signal and indicative of subterranean details adjacent to the instrument. A battery temperature is sampled at every predetermined timing, and a change in battery temperature rise gradient is computed each time the battery temperature is sampled. This throttle position or load value is independent of the actual displacement of the variable displacement internal combustion engine. The front-side connection and the backside connection are co-located with respect to each other on a given stratum from among the two or more strata, and are respectively connected to different ones of the multiple circuit components on the given stratum.