3. Inspection and Adjustement l Measurement with hydrometer When using a hydrometer, the measured specific gravity must be corrected accord- surement. The specific gravity of battery ing to the temperature at the time of mea- electrolyte is defined with 20°C as the standard. Since the specific gravity in- creases or decreases by 0.0007 when the temperature varies by l”C, correct the value according to the equation below.
D = St + 0.007 (t - 20) Battery charge meas with a hvdrometer 1 Electrolyte tempera- ture at measurement L Specific gravity at mea- surement Rubber bulb L -Converted specific gravity at 20% Glass tube Specific gravity and remaining battery charge I Specific 1 Discharged 1 Remaining1 Hvdrometer structure 1.160 50 50 1.210 25 75 1.110 75 25 1.060 100 0 Terminals Clean if corroded or soiled. Mounting bracket Repair or replace it if corroded. Retighten if loosened. Battery appearance How to read hydrometer Replace the battery if cracked or de- formed. Clean with fresh water if contaminated. 3-12