ppm和ppt的定义如下：
1ppm = 1/106 = 10-6
1ppt = 1/1012 = 10-12
因此
1ppm = 106ppt
百万分之几xppm 等于万亿分之几xppt 除以106:
xppm = xppt / 106
示例：7000ppt等于0.007000ppm：
xppt = 7000ppt / 106 = 0.007ppm
| ppt | ppm |
|---|---|
| 1 | 0.000001 |
| 10 | 0.00001 |
| 100 | 0.0001 |
| 1000 | 0.001 |
| 10000 | 0.01 |
| 100000 | 0.1 |
| 106 | 1 |
| 107 | 10 |
| 108 | 100 |
| 109 | 1000 |
| 1010 | 10000 |
