One doesn't need a digital scale to detect a 25x error. The crude,
inaccurate marks on the side of the mixing cup are good enough for that kind
of error check.

When I worry is when the pump sucks air and emits bubbles after the jug is
refilled. Then it's a SWAG.

Roger

http://home.earthlink.net/~derbyrm

"Oddgeir Kvien" wrote in message
...
I always uses a digitale scale to check the amount of resin and harner,
even if I use calibrated pumps.