A convenient electromechanical instrument has been developed to take the place of sets of sensitive hydrometers in measuring liquid densities. The range covered by the particular design is 0.8000 to 1.0000 and could be extended without impairing its accuracy. Temperature‐controlled liquid samples of 100 cc are used. The instrument derives its sensitivity from a miniature differential transformer and associated transistor electronics. One of the primary advantages of the device is positiveness of reading.