A magneto-optic probe was used to make time-resolved measurements of the magnetic field in both a single supersonic jet and in a collision between two supersonic turbulent jets, with an electron density ≈ 10 18 cm −3 and electron temperature ≈ 4 eV. The magneto-optic data indicated the magnetic field reaches B ≈ 200 G. The measured values are compared against those obtained with a magnetic induction probe. Good agreement of the time-dependent magnetic field measured using the two techniques is found.