A probe for insertion into the body of a subject includes a sensor, a first microcircuit, which stores first calibration data with respect to the sensor, and a first connector at the proximal end of the probe. A probe adapter includes a second connector, which mates with the first connector, a signal processing circuit, which is processes the sensor signal, and a second microcircuit, which stores second calibration data with respect to the signal processing circuit. A microcontroller in the adapter receives the first and second calibration data and computes combined calibration data. The adapter includes a third connector, which mates with a fourth connector on a console. The console includes signal analysis circuitry, which analyzes the processed signal using the combined calibration data provided by the probe adapter.