This instrument measures the salinity and specific gravity of seawater, and utilizes a new material that is durable against salty samples, The salinity of seawater is displayed in parts per mill (‰). The MASTER-S/MillM is a good alternative choice when the water resistant feature is not a priority and the Temperature Compensation will be carried out manually.For the model with Automatic Temperature Compensation please choose MASTER-S/Millα