Comparing volume concentration and mass concentration
How does µl/l and mg/l compare?
[Sequoia, April 7, 2010]
A question that Sequoia often gets asked is: How does the volume concentration (in units of µl/l) from the LISST compare to mass concentration in mg/l? And how do I convert µl/l to mg/l if I know the density in g/cm3 – the units do not seem to agree?The answer is as follows:
A volume of 1 l equals 1000 ml or 1,000,000 µl. So there are 1,000 µl / ml, and 1 ml = 1 cm3. Therefore 1µl = 1×10-3 cm3.
Consequently, a volume concentration of, say 15 µl / l is equal to 15×10-3 cm3 / l.
Now, if the density of the particles is 2.65 g/cm3, then the mass concentration is computed as
15×10-3 cm3 / l × 2.65 g / cm3 = 39.75×10-3g / l = 39.75mg / l.