 If you have Lead Acid
Batteries an Accurate Hydrometer is a Must
An accurate hydrometer is
essential to good battery care. Specific gravity is the best measure of a lead
acid battery's state. We know of no better hydrometers than those
manufactured by Francis L. Freas Glass Works Inc. Freas hydrometers are
guaranteed to remain accurate throughout the entire life of the instrument.
The 'basic'
Freas No.1 battery hydrometer
measures specific gravity from 1.250–1.275 graduated in 0.002 degree.
The one ounce rubber bulb and end
piece are made from the highest grade acid resistant rubber.
 
Temperature
To secure a correct specific
gravity reading of the electrolyte in a battery, the temperature of the
electrolyte must be taken into consideration because specific gravity changes
with the temperature. A Hydrometer containing a thermometer for measuring
the temperature of liquids is called a thermohydrometer.
The Freas No.98 Hydrometer
Set with Thermometer measures specific gravity from 1.140 to 1.300
graduated in 0.002 degree
divisions. The
thermometer measures temperature from 30 to 120 F. The two ounce rubber bulb and
end piece are made from the highest grade acid resistant rubber. Overall
length of the assembled hydrometer is 18 inches.
Freas Pilot Cell Thermometer
9½" Pilot Cell
Thermometer 30–120 Deg. Fahrenheit graduated in single degree divisions and
numbered every ten degrees. The Freas No. 119
Pilot
Cell thermometer also has a specific gravity correction scale in red giving
the corrections for the temperature of the electrolyte.
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