re: IVAC fill level meter

After having spent half a day in the on-and-off rain vibrating the dust out of my clogged filter, for the hundredth time it seems, now I find this.  Well, better late than never.    If they did the IR light pulse coding properly, then a film of dust on the sensor lenses should not be a big problem.  Same principle as a laser tape measure.  But still .... Murphy.  

 Let us know how this works out. I'll get one forthwith if you have good luck with it.