Manual methods are being replaced by digital density meters for many critical reasons. Even though digital density meters are more expensive, it is a necessary investment.
This comparison datasheet gives a description, applications, and advantages and disadvantages for the following instruments:
Manual methods for density measurements: Manual methods like pycnometers and hydrometers are widely used for the determination of density and related values, e.g. specific gravity, alcohol%, BRIX°, API degrees, Baumé, Plato, etc. Although these methods are easy to use and quite inexpensive, they require expertise in every step of the manual operation protocols, which often affects the accuracy and reliability of the results. Most often, different operators will obtain different results for the same sample.
Digital methods for automatic density measurement: Digital density meters use the oscillation tube technology to measure very accurately the density of a sample in a short time. In addition, benchtop digital density meters use a built-in Peltier thermostat to control the temperature of the sample. The measurement is started by pressing a key, after a short time the result appears on the screen and can be printed, sent to a computer or exported to LIMS.