做一张表，看起来清楚一点
| 基准 | 2.49835 | 5.00326 | 7.49905 | 10.00351 |
| 有电(9v电池) | 2.498 | 5.003 | 7.5 | 10.006 |
| 9v(稳压电源，下同) | 2.497 | 5.002 | ||
| 8v | 2.497 | 5.002 | ||
| 7v | 2.497 | 5.002 | ||
| 6v | 2.497 | 5.002 | ||
| 5v | 2.497 | 5.002 | ||
| 4v | 2.494 | 4.997 | ||
| 3v | 1.4152 |