Float 2 is suspended on helical spring 3 whose force counterbalances the buoyant force of the float. When the liquid to be tested is delivered through input tube 1, recording pen 4 draws a line whose length corresponds to the density of the liquid. The instrument operates periodically. When vessel 5 is filled with the liquid to the height of the top bend of siphon 6, the liquid begins to empty the vessel through the siphon. After vessel 5 has been completely emptied by siphon 6, it begins to fill again.
$4082$EHP,M$