通常计算海水当场密度ρ值(或海水比容偏差δ值)时,不是利用一些表格,便是使用一些图线,先将海水的条件密度σ_t 值计算出,然后经过关于温度—压力、盐度—压力以及单纯的压力等的订正,才能将最后的ρ值(或δ值)算出。即使不考虑上述这些订正值,仅计算一个σ_t 值.就是一件很费时间的工作,如需要大量计算时,那就要花费很多的时间了。 Generally, when calculating the on-site density ρ of seawater (or δ value of seawater specific volume deviation), we use some graphs instead of some tables to calculate the conditional density σ_t of seawater first, and then calculate the σ_t value of seawater with respect to temperature-pressure, salinity - Pressure and simple pressure correction, in order to the final ρ value (or δ value) can be calculated. Even without considering these corrections, only calculating a σ_t value is a very time-consuming task, which takes a lot of time if it requires a lot of computation.