A Practical Manual On Sea Water Distillation
With A Description Of The Necessary Machinery For The Process

IO8 SEA WATER DISTILLATION. denoted by the salinometer is altogether delusive, as will be seen by referring to Table C C, p. 26. Note.—If the brine to be tested has a temperature lower than 200°, the reading of the salinometer requires adjust- ment. Thus, with brine at 200°, the salinometer will indicate whereas at 180° the reading will be and at 160° it will be although the actual strength is A- The figure 0 is the line the salinometer will sink to if put in fresh water (at 200°). These salinometers do not usually record a greater salinity than ;s42, at which point there is usually a danger signal, to show the salinity is too great to be safe. Note.—In connection with the use of the salinometer, the part of Chapter m. dealing with “ Density ” and “ Salinity ” should be read. A salinometer is really an instrument for ascertaining the “ salinity ” of the water it is placed in—i.e., to show its buoyancy as compared with that of ordinary water. Specific gravity is the weight of a substance in comparison with an equal volume of dis- tilled water at a temperature of 60°. The salinometer really indicates the relative buoyancy of salt water as compared with that of ordinary water at 200°. The salinometer is a delicate instrument, and if the bulb or hollow sphere is bruised, or the metal is allowed to be covered with scale, its accuracy in recording salinity will be much impaired. It should also be mentioned that salinometers are not always correct. They have been known to vary considerably when three or four salino- meters of different makers have been put in the same solution at the same temperature.