With an 11-inch concentric searchcoil, this metal detector can scan for objects nearly a foot underground. While you’re scanning, the screen shows you a target ID number corresponding to the type of metal you’ve found. A tab also lights up to give you an even better idea of what the treasure might be, differentiating between iron, a quarter, a silver dollar and so on. This way you won’t have to memorize as many target ID numbers. If you need a little help getting started, a handy chart is available in the instruction manual so you can see what target ID numbers correspond to which metal.
The Delta 4000 has eight levels of sensitivity ranging from 4 to 12. The factory setting was 8, and we found we didn’t have to change it to get readings on the various metals we buried. It automatically searches in discrimination mode, which excludes iron from your treasure hunt. You can customize this mode to eliminate more kinds of metal. You can also use the notching mode to selectively include or exclude a single type of metal. Pinpoint mode can give you an even better picture of what you might have found. This metal detector also has volume control so you can turn down the beeping if it’s getting on your nerves.
In our tests, the Delta 4000 picked up 82 percent of the objects we buried, the second-highest pickup rate of the detectors we tested. The Bounty Hunter Titanium Camo was the only device that found more objects. The Delta also correctly identified 54 percent of the objects we buried, one of the higher accuracy rates in our lineup. Disappointingly, it did not pick up most of the silver items we buried, though it did well with brass, zinc and aluminum.
This metal detector displays depth on a five-notch scale. One highlighted notch means the object is between the surface and 2 inches underground, and the more notches that light up, the deeper the object is, reaching 8 or more inches at five notches. The instruction manual says the 11-inch coil can search up to 11 inches deep but that accuracy diminishes once an object is buried 8 inches or deeper. In our tests, the Delta 4000 got an accurate depth reading 32 percent of the time, a mid-range accuracy rate compared to other models.
When the Delta 4000 discovers an object, we noticed the reading stays displayed on the screen for anywhere between five and 10 seconds. This was nice for our data gathering process, but it also means you need to sweep this detector very slowly. The reading stays on the screen while you continue to move, so you have to listen to the machine’s beeps to pinpoint an object’s exact location. This isn’t necessarily a bad thing but merely a unique quality that took time to adjust to.
This metal detector is easy to put together. You simply slide the pieces into place and they interlock. It runs on a 9-volt battery, giving you 20-25 hours of use before you have to replace it. This is standard among the metal detectors we tested. Teknetics also provides a five-year warranty, which is the longest in our comparison except for the Tesoro Mojave that has a lifetime warranty.
The Delta 4000 weighs 2.3 pounds and is one of the lighter machines in our lineup, so your arm won’t get tired quickly. Arm fatigue can be counteracted with an armrest strap that attaches to the detector and loops around your forearm. The Delta 4000 doesn’t come with one like the Garrett Ace 400 does, but the arm strap is available for purchase separately.