Go back to the bURNINGvAN beach.  Fill a small plastic bag with one cup of
sand.  Remove the 182B turn it on it's back.  Fill it with sand using a 1
cup measure, counting how many cups to fill it.  Dump the sand out of the
182B.  Weigh the plastic bag.  Now convert cups to ounces volume, ounces to
cubic inches and voila you know how many ounces  volume, quarts, cubic
inches or ounces weight , or pounds of sand that the 182B will hold.  For a
truly accurate measure make sure there aren't any tootsie rolls from your
dog in the sand else you'll have to clean out the fridge.  Of course that's
why to use a cup so you avoid those little extras.  Put the 182B back in the
van, make suitable notations on your unit as to what you found out.  You
will also gain the knowledge of just how much is 'pound sand' perhaps useful
in quasi-intellectual encounters in the future.

Pound sand=Pound salt by weight.  Ounce sand = ounce salt by volume

Time flies like an arrow, fruit flies like an old banana.

Fizzix again.