Thank you Zircon for sending this StudSensor HD70 to review!

I have reviewed a lot of things (close to 550!) but this is almost certainly my first stud finder. I have to admit I did not expect Zircon to send this to us after being given the opportunity, but I am certainly grateful for the chance!

I've been married for a bit over twenty-five years. When we moved out and bought our first house those many moons ago, my dad was kind enough to give us a bunch of older tools that he didn't need anymore, or perhaps that we needed more than he did. Among that bunch was a Craftsman Stud Finder, a tool that I have used and has operated without fail for decades - other than a missing back cover, it still works. I vaguely remember my dad getting it in the 1980s most likely, and based on cursory research, it was probably made by Zircon for Sears/Craftsman. The reason I believe Zircon made my 'classic' is because they held the patent on the technology until 1998 when it expired. While there are a lot of stud finders on the market now, you have to give respect to the original patent holders, and Zircon is that company. Sadly, Sears is all but no more, and Craftsman is a shadow of its former self. Times sure have changed. And, apparently, so have stud finders.

The basic operation between my classic and this new one is pretty similar: place the StudSensor on the wall, press and hold the conveniently-placed button, and move the StudSensor slowly in one direction (usually left or right) on the wall (perpendicular to the expected direction of the studs) until the sensor triggers and you hear a 'beep'. This shows you are over a stud, though where it beeps has slightly changed in this new version.

In the 'classic' model, it would beep whenever it detected a stud. So as the user, you would have to carefully move it to determine what you thought was the edge, and then note the center of where the beeps stopped, and hope you guessed correctly. My model did offer a deep scanning option, but that's about where the features started and ended. While in many ways finding studs seems pretty similar to my classic, once you understand the new features, it's actually much easier - and safer, too.

You see, this HD70 has a few options that makes it much better than before. The main stud-sensing power is expanded to detect edges and the center, with the bright blue LCD screen glowing and displaying the word 'EDGE' on the edge, and 'CENTER' when you reach the center. There are vertical bars that show you an approximate proportion that it is between each edge, giving you an idea of how much farther you need to move it. If the backing board is too large it gets a bit confused, but seems to still work okay. It seems to work through thick or thin surfaces, and detects wood or metal equally. (Higher-end models can tell you if it's wood or metal.)

Perhaps the most important new feature is WireWarning detection. In my testing, I found that it will trigger whenever there is bare live wire behind the wall. This is particularly important in houses or other structures that use Romex-style wiring, rather than conduit. This finder is not designed to detect conduit; in my testing it might if the metal tubing is right up against the drywall, but won't otherwise. It isn't a designed or advertised feature, so no harm no foul. Thankfully, stray screws very rarely go through conduit pipe anyway, so it's not a big deal.

I will say that I wish I had this StudSensor with WireWarning a couple of years ago, when I went to hang up something my wife wanted in our mud room. As it turns out, our breaker box is also in that room, and putting a screw in the wall caused a light switch to stop operating. I must say that this could have been much, much worse - an electrical fire or even being shocked to death could have resulted. Thank God that He was looking out for me that day. In any case, backing out the screw fixed the light... Going forward, I will be using this StudSensor with WireWarning before hanging anything else up, especially upstairs which was built with Romex wiring rather than conduit (like my more recently built-out basement).

I found that other wires that had decent current would sometimes be detected, but something low-voltage would not. For example, active USB charging cables would sometimes be detected, as would PoE (power over Ethernet) live cables. But inactive/unplugged cables, or data-only Ethernet would not be. I suppose that makes sense, since it probably looks for induction fields that low-voltage or unplugged cables would not emit.

One little goofy thing that I didn't expect to like so much is that this HD70 not only has a notch in the center to make it very clear what 'CENTER' means on the stud you found, but also a glowing red arrow that appears on your wall, making where you should nail or drill about as clear as it gets. It's a nice touch.

If something is not detected in the default StudScan mode, there is a DeepScan mode that you access by pressing and holding the button twice in quick succession. The funny thing is that I almost never needed to use the more sensitive mode; StudScan worked almost always. It's still great to have that more sensitive mode just in case. It's meant for walls or other boards over 1 1/2" thick.

The Zircon StudSensor HD70 is a nice, mid-range stud finder that honestly every homeowner should probably have. Looking at the current Zircon HD series product stack, the step down model doesn't detect stud centers, but is otherwise pretty good. The model below that loses deep scanning, and below that loses WireWarning - something that I strongly recommend be present in any stud finder application after my close call almost meeting Jesus early. Models above this have metal and electrical modes, and the top of the line has even more features. Recommended for anyone handy or any homeowner who might hang anything on their walls!