| 摘要 |
PURPOSE:To attain reduction of consumption of current, i.e. long lifetime of an incorporated battery, by a method wherein detecting means disposed three-dimensionally are driven in a time-sharing manner for each measuring period. CONSTITUTION:Signals of an X-axis detecting means 1, a Y-axis detecting means 3 and a Z-axis detecting means 5, which are amplified by an X-axis amplifying means 2, a Y-axis amplifying means 4 and a Z-axis amplifying means 6 respectively, are selected by a multiplexer 8 in accordance with a control signal 18 which an operation control means 7 generates from output signals of a timing generation means 12 and a frequency-dividing circuit 11, and converted into digital values by an A/D conversion means 9 in accordance with a control signal 22. Next, and arithmetic means 13 converts electric signals from the conversion means 9 into magnetic field strengths and computes an actual magnetic filed strength from the components of the magnetic field strengths on the axes X, Y and Z. Moreover, the arithmetic means 13 executes computation of the product of the computed magnetic field strength and the time of a measuring period, adds it to the content of an integrated value storage means 14 and stores the result therein again. The content of the storage means 14 and the content of a time counting means 15 counting the entire measuring time from the start of measure ment are displayed in a display device 17 through the intermediary of a display control means 16. |
