IEC 60258: Direct-Acting Electrical Indicating Instruments — Panel Meter Accuracy

Why a Class 1.5 Panel Meter Has ±15% Error at 10% of Full Scale

IEC 60258 specifies direct-acting analogue indicating instruments. Class 1.5 means ±1.5% of full scale — but relative error is ±15% at 10% of scale. Always select ranges where readings fall in the upper 60–100%.