| 1. | The piezometric head is also measured from the same datum level .
测压水头亦应从同一基准面算起。 |
| 2. | Depths below datum are calculated from the corrected reflection times .
基准面以下的深度，需要根据作过校正的反射波时间来计算。 |
| 3. | This fixture should be provided with a reference leveling surface, so that it can be kept level as the balance deflects .
这种装置应该有一个水平基准面，以便在天平变形时能够使之保持水平。 |
| 4. | All elevations are relative to chart datum
所有标高均相对于海图基准面。 |
| 5. | Chart datum for inland navigation
内陆航行图深度基准面 |
| 6. | Tidal height datum plane of the station
测站潮高基准面 |
| 7. | Machine center to back
机床中心至工件安装基准面 |
| 8. | Assuring rate of depth datum
深度基准面保证率 |
| 9. | Chart datum : the level to which soundings or tide heights are referenced
海图基准面：测量水深或潮水高度的基础高度。 |
