Temperature Correcting Battery Hydrometer
Professional type    Built-in thermometer for temperature correction    Give accurate battery charge condition            To Prepare for Use:       Carefully remove the rubber bulb and plug from the glass tube and remove the foam protector from around float.    Wet and reinsert float, plug, and bulb.    Extend rubber bulb on top of glass tube.       Instructions for Use:    Insert rubber tip into cell of battery.  Hold instrument in vertical position.  Squeeze bulb and draw enough liquid to float hydrometer freely, watching to see that top of float stem does not touch rubber stopper at the top of barrel.    The mark on the hydrometer float which is in line with the surface of the liquid indicates the uncorrected specific gravity.  Add or subtract specific gravity points to float reading as indicated by the thermometer at the bottom.  The result of the corrected float reading gives the precise specific gravity and indicates the condition of the battery.    Specific Gravity Reading:        1.260 sp.gr.  100% Charged      1.225 sp.gr.  75% Charged      1.190 sp.gr.  50% Charged      1.155 sp.gr.  25% Charged      1.120 sp.gr.  Discharged        Return liquid to same battery cell from which it is taken.    Cell Variation:    Variations of 20 or more specific gravity points between battery cells indicates a bad or weak battery.     NOTE:  A proper test cannot be made unless each battery cell has sufficient electrolyte to permit hydrometer float to rise freely.  An accurate reading cannot be obtained immediately after water has been added to cells or at below freezing temperatures.  Water must be allowed to mix with electrolyte.