The magnetic field between the electrodes of an 80 J ablative pulsed plasma thruster was both measured and determined analytically. This was done to better understand the acceleration process and assess the accuracy of the analytical method. The measurements at different positions in both breech-fed and side-fed propellant configurations were performed using a shielded induction probe of 1 mm in diameter. To calibrate the probe, a Helmholtz coil was built. The magnetic field was calculated using the law of Biot-Savart and assuming a current sheet thickness of 3 mm. The measured magnetic field showed an overall peak at 0.7 T. It was possible to confirm the induced current loop formed between the electrodes at the time when the overall current passes through zero. The comparison between the magnetic field model and the measurements at the propellant surface of a breech-fed thruster showed reasonably good accordance.