For those of you that don't want to shell out the big bucks to purchase a D.O. meter, or just can't justify the price for the few times you would use it, this may be what you're looking for. I just saw this in a sale catalog I got from Ben Meadows 1-800-241-6401.
I've seen similar ones run up to 3 or 4 hundred dollars i.e. a Kemmerer (sp?) sampler made of brass. Back in the old days of my youth working for the DNR back in the 70's this is the kind of thing we used to test D.O. PH, alkalinity etc right in the boat.
Of course you'll need a test kit separately to test the water samples, but it would still be cheaper than buying a meter.
Not plugging the company but thought this might be of help to someone. I have ordered from the company and they ship out fast. Also a lot of neat outdoor things in their catalog.