I think you meant coins, not chips. Coins get melted down (it takes forever). Tech chips as far as I know are just there for when you need them, no need to process them further after they are found or printed.
As for the detector, here are a couple of pointers:
The actual reward you get it completely random, so it doesn't matter where you search. The reward can only come if the beep is happening though, so be sure to keep the target pointed at some sort of ground. Rocky areas and shallow water are not good hunting ground. Also, since it's completely random, I tend to stay out of heavy shrubbery as it makes it really hard to see the dirt pile when it appears.
Rather than meander, I like to just plow forward in a giant loop around the island. That way if I hear the high pitched sound, all I ever have to do is hit the S key to back up a step or two (depending on how fast your reaction time is) and the pile is always right there.
Another reason to just plow forward is that the developer has stated that once a reward has spawned, the entire nearby area becomes much less likely to spawn another one. Just remember, you're not actually hunting for anything that has been pre-placed. The game actually spawns the rewards in real time as you go.
Tech Chips are by far the rarest drops it seems. Coins are rare as well, but a little more common than Chips. Another somewhat rare drop is a Static Pearl, but much more common than either Chip or Coin. Unfortunately there are a lot of junk items you pick up. Can't be helped.
