Popsicle stick scale. Easy to make AND you get to eat popsicles to make it. Might be cheaper to buy a digital scale from Amazon. I paid less than $15 for mine. It wasn't as tasty though.
I have a BritFit from Amazon . $15.99 ! Great scale .Amazon.com: (NEW VERSION) Brifit Digital Mini Scale, 200g /0.01g Pocket Scale, 50g calibration weight, Electronic Smart Scale, 6 Units, LCD Backlit Display, Tare, Auto Off, Stainless Steel (Battery Included): Kitchen & Dining
I can usually tell copper from zinc by sight. But an electronic gram scale is inexpensive. (With at least tenths.) The zinc cents will be shiny from the plating, and you can often see the zinc color under a break. The copper will be (cough, cough) copper colored. After looking at millions of coins (even when I weigh them to double check) I am rarely wrong. Here's a hint. If it's a small date 82-D, it's 2.5 grams, zinc.
you can make a pop sickle scale easy and tare it out with a pre 81, and check it with a post 83. I use mine all the time to check 83s...so i dont have to use my digital.