I'll second Korumkids recomendation for the Keenets Weighlite scales. Had a pair for nearly 10 years now and they are still going strong - and accurate too. I bought a second set a few years ago - being paranoid about accurate weights i like to check one set against the other - just to be sure!

I had the older set checked by weights and measures after a PB last year and they were spot on! They even come with their own sling which is the perfect size for barbel, its a simple job to zero the wet sling before weighing the fish. Lets be honest - if you are going to take the time to weigh a fish you might aswell do it accurately! I'd stab a guess Glen that unless you use a particularly small korum net it weighs a fair bit more than 1lb when wet! Most barbel spoons i've used come in between 1lb 4oz and 1lb 12oz depending on frame size and mesh type.