hows this thing work?

i pick up an old battery cell tester today. i aint got a clue how this thing works?

it is made in an H shape with a woodin handle 2 metal barbs and a dial.

this thing must of been made be for my time.


any ideal how it works?

 

probably works on the old batteries that have the cell connections on top...won't work on a new ones...

 

They were used on the old tar top batteries to measure the voltage of the individule cells. They would be poked into the lead cell connectors on the top of the battery. Will not work on the new sealed type batteries.