摘要 |
1456270 Determining specific gravity electrically COMPAGNIE EUROPEENNE D'ACCUMULATEURS 4 March 1974 [12 March 1973] 9715/74 Heading G1N [Also in Division H1] A device for indicating a threshold value of density of a liquid 2 e.g. the electrolyte of a storage cell includes a tube 3 open at both ends and partly immersed in the liquid and containing a column of a second liquid 4 immiscible with the first, and two thermistors 9, 10 arranged respectively in electrical heating elements 7, 8 in the first and second liquids the bottoms of the respective thermistors being spaced apart vertically by a distance #H corresponding to the difference in free surface levels #H of the liquids when the electrolyte density is at the threshold level. The thermistors constitute adjacent resistance arms R 1 , R 2 of a first bridge circuit monitoring the density threshold. The resistance arm R 1 is also in a second bridge circuit monitoring the level of the first liquid. |