THE HYDROMETER TEST

Radio Record, Volume I, Issue 52, 13 July 1928, Page 13

THE HYDROMETER TEST

A SERVICEMAN states that it is quite a common occurrence for a battery owner to take his own hydrometer test of an accumulator and receive a quite erroneous idea of the state of the battery unless the specific gravity of the acid solution to be used is stated on the battery itself. Because one particular make of battery should read 1800 on the hydrometer when fully charged, it does not follow that all other fully charged batteries should give the same reading, so that before passing judgment on a charging station it is, necessary to know what is the correct specific gravity for the acid when the battery is fully charged. here have been many occasions on which immediately after delivery of his recharged battery. the owner hes

telephoned to the service station a complaint that his battery is only halfcharged. This mistaken idea is due to the fact that the owner of the battery makes his hydrometer test with-. out being aware of the actual reading required for that particular make of battery. It is obvious therefore that battery-owners should, make a point of ascertaining what hydrometer reading to expect when their battery is fully charged. Then if the reading is found to be low, it is probable that the charging station has not finished its work. Articles on the use of accumulators usually deal with average figures applicable to any accumulator in case of the manufacturer’s recommendations not being available, but it is certainly better to work by the latter. The correct charging rate is also important and should not be exceeded if the battery is to have a long life.

CUCU QUERIES BY CORRESPONDENCE. 1. Every communication enclosing queries ig to be addressed to ‘"Megohm,’* Box 1032, Wellington, and must be accompanied by a stamped addressed envelope for reply by post. 2. Questions must be written so that a space is left in which the reply may be added. 3. No charge is made for replies.