Which statement about hydrometer readings for lead-acid electrolyte is correct?

Which statement about hydrometer readings for lead-acid electrolyte is correct?

• A. The hydrometer reading requires temperature correction at 80°F
• B. The hydrometer reading does not require temperature correction if the electrolyte temperature is 80°F
• C. Hydrometer readings are not used for lead-acid electrolyte
• D. Temperature correction is required only when electrolyte is below 32°F

Answer: (B)

Hydrometer readings for lead-acid batteries are calibrated at a standard temperature, typically 80°F. The electrolyte’s density changes with temperature, so to interpret a reading correctly against the chart, you either apply a temperature correction or ensure the electrolyte is at the calibration temperature. If the electrolyte is at 80°F, no correction is needed—the reading already matches the standard scale for that temperature. The other statements aren’t accurate: correction isn’t required at 80°F, readings are indeed used for lead-acid electrolyte, and temperature correction isn’t limited to conditions below freezing—any deviation from the calibration temperature requires adjustment.

Hydrometer readings for lead-acid batteries are calibrated at a standard temperature, typically 80°F. The electrolyte’s density changes with temperature, so to interpret a reading correctly against the chart, you either apply a temperature correction or ensure the electrolyte is at the calibration temperature. If the electrolyte is at 80°F, no correction is needed—the reading already matches the standard scale for that temperature. The other statements aren’t accurate: correction isn’t required at 80°F, readings are indeed used for lead-acid electrolyte, and temperature correction isn’t limited to conditions below freezing—any deviation from the calibration temperature requires adjustment.