| 摘要 |
PURPOSE:To obtain a specific gravity sensor, which has less self-discharge and displays stable potential difference even under shocks and vibration for a long time, by coating a lead electrode and a lead dioxide electrode by a porous tube having acid-resistance and oxidation-resistance properties such as glass fiber. CONSTITUTION:A main body 1 of a sensor comprises a synthetic resin and attached to a battery by a threaded part 2. A conating tube 3 of about 6mm.<phi> made of braided glass fiber coats a positive active material (PbO2) 6, whose raw material is lead powder, and a negative active material (Pb) 4, whose raw material is also lead powder, so as to prevent their falling and to prevent the direct contact of bubbles and fine particles to the positive and a negative active materials from the outside. Current collecting bodies 5 are formed by lead wires. The tube 3, in which the materials 4 and 6 are sealed, is closed by a bottom lid 7. Therefore the amount of self-discharge is few, the sensor is stable against shocks and vibrations, and the specific gravity of electrolyte can be accurately displayed for a long time. |
