Improved magnetic retarding system for watthour meters

Because of the squared relationship between the flux and braking torque of the retarding magnet of the watthour meter, and the need to maintain high meter accuracy under all operating conditions over long periods of time, stability of the magnet is essential. Over the years, this stability and the resistance to demagnetization by extraneous magnetic fields or short-circuit currents have increased with each new material development applied to the retarding system of the meter. A continuation of this series of improvements is currently taking place with the introduction of rare earth magnets.