Hyp-o-meter - what's that?

*bay item #190500388723. Does anyone know what is that, and how it works?

At a guess it measures conductance in the wash water and somehow correlates that with the hypo concentration. The ceramic gizzies on the electrodes are probably an attempt to avoid electrode polarization with presumed DC excitation. (i.e. - it's an ohm meter)

I don't think this works very well based on the observation that if it did then there would be products like it on the market today.