Just because it's digital doesn't mean it's more accurate....just easier to read. Most people don't calibrate meters often enough, not to mention most meters were never intended for exposure to salt water, they were brought into our industry by some company that saw a potential sale. Keep in mind a $20 test kit that does 20 tests [essentially $1 per test] and your asking your eye to distinguish a "hue change" not color change for most kits, and you want to know the difference between ppm [that's parts per million, an infinitely small number] - your asking a lot for a $1. Regardless of test kit, give up on knowing a number, be happy with a range and use multiple kits.