Low frequency magnetic field effects on computer monitors

This paper discusses the effect of external low frequency magnetic field on computer monitors. To characterize the disturbance caused by the magnetic field, test setup with quantitative measuring method has been developed by ASU. Various computer monitors have been tested and the effect of different parameters like monitor size, refresh rate and screen resolution have been evaluated. Also the effect of harmonics on the interfering magnetic field has been investigated. These studies are needed to formulate a solution to eliminate these disturbances and as a help to develop a national standard. Based on the measurements, monitor sensitivity is specified and values for typical monitors are presented. If was found that about 15 mGauss magnetic field may cause perceptible disturbance on the 14'' monitor's screen and this sensitivity drops to around 5 mGauss in the case of a 21'' monitor.