| 摘要 |
<p>A counter (7) for counting signals having a substantially single frequency when a physical quantity is constant, wherein the physical quantity has a linear relationship with the signals. The counter includes a counter (73) configured to count the number of input signals during given counting intervals and a counting result correcting unit (74) including: a period measuring unit (740) configured to measure signal periods of the input signals during the counting interval each time each input signal is inputted; a frequency distribution generator (741) configured to generate a frequency distribution of the signal periods during the counting interval, based on measurement results from the period measuring unit, wherein the frequency distribution represents a distribution of frequencies for each of class values; a representative value calculator (742) configured to set one of the class values as a representative value for the signal periods, based on the frequency distribution, wherein the representative value has a maximum value obtained by multiplying the class value by the frequency corresponding to the class value; and a corrected value calculator (743) configured to calculate, from the frequency distribution, a total number Ns and a total number Nw n so as to correct the number of the input signals counted by the counter, wherein Ns represents total of the frequencies of the class values that are less than 0.5 times the representative value, and Nw n represents total of the frequencies of class values that are equal to or greater than (n + 0.5) and less than (n + 1.5) times the representative value.</p> |
