I'd do two things...
First, get a can of lubricant like WD-40, and coat the entire scale with a good coat. (and repeat every year)
Second, get a piece of rubber to cover the scale part. I would not do it for the platform section as it's hard to do without locking in moistire. But for the scale section, you can use a rigged piece of rubber, ensuring the there is enough air flow to not trap moisture under the rubber. As long as you keep it covered and rain out, it should work well.