| 摘要 |
PURPOSE:To improve measuring accuracy, by immersing a pair of electrode comprising lead and lead dioxide in the electrolyte of a battery, immersing another pair into sulfuric acid having a constant specific gravity filled in a container, which is immersed in the electrolyte, and connecting both electrode systems so as to offset the potential differences each other out. CONSTITUTION:An electrolyte 2 comprising dilute sulfuric acid is sealed in a battery jar 1. In the electrolyte 2, a plate group 5 comprising positive plates, negative plates, and separaters, is immersed. A reference electrode part 9 comprises a pair of a lead electrode and a lead dioxide electrode. The electrodes are constituted of the same electrodes as those in a specific-gravity detecting electrode part 6. The electrode part 9 is immersed into a container 11, which is filled with sulfuric acid 10 having a constant specific gravity, and immersed in the sulfuric acid 10. The container 11 is immersed in the electrolyte 2, and the electrode part 6 is also immersed in the electrolyte 2. The electrode parts 6 and 9 are connected in the direction where the potential differences are offset. A potentiometer 7 is connected to the electrode parts 6 and 9 so as to display the offset potential difference. Thus the sensitivity of the measuring instrument is increased and the change in potential difference due to temperature change in electrolyte is compensated. Therefore highly accurate measurement of the specific gravity can be performed. |
