Hmmmm, the DIC-20 is a solid unit and that's even attached to the cart. The metal that you screw the housings into is painted and I think it would withstand the outdoors pretty well, but the bolts may end up rusting over time. I also thing the blue plastic casings would suffer from the outdoors over time as well.
However!

(you knew this was coming) I think that if you were to give the unit some detailing love on a consistent basis, it'd last well outdoors. Rinse it down once a week depending on usage, spraying some Optimum Protectant+ or the like on the blue housings to keep it protected from fading/cracking, maybe some 845 IW on the painted steel parts and bolts...then the only thing I'd be worried about is the PPM meter.