Abstract: "A small low impedance flux monitoring device has been built which utilizes the heating (and consequent chance in resistance) of a boron coated platinum wire. Feasibility tests in the Argonne-GP-3 reactor indicate that it may develop into a wide range instrument, particularly useful at high flux levels. Design and constructional details of the bolometer and its associated circuits are given. The circuitry is somewhat unique since it is in effect an all electronic self-balancing bridge. Future lines of research are suggested to solve some of the remaining problems."