Pellet air gauge

Im looking to purchase or build an air gauge for measuring pellet head size. Problem is I cant find one for sale, and ive never seen one in person to know exactly what it is or any dimensions. Does anyone know where I can find one for sale, or where I could borrow one for a day or 2 to get some pictures and measurements. Ive tried reaching Dan Brown and Mark Buchanan as these are the only 2 I know of that have built them and have had no luck finding any contact information for either. If anyone can help, shoot me a PM...



P.S. I already have the pelletgage....looking for something more accurate

thanks in advance!!