Stanley 77-110 IntelliSensor Stud Sensor

by Stanley

Product Description

From the Manufacturer

Pocket-size stud sensor detects and locates studs and joists up to a 3/4" depth. LED display and buzzer indicates stud edge. High-impact, ergonomically-designed ABS case includes pencil notch for pinpoint marking. Calibrates automatically for surefire accuracy. LED's include low battery warning. Requires 9-volt battery (not included). This product, launched in July 2003, was first available at participating Preview Dealer stores.

Product Description

Locates the edges of studs or joists through drywall and other common wall materials at a maximum depth of 3/4''. Electronic audio and visual signals are emitted once the edge of the stud is detected. Automatic shut off for longer battery life. Pencil notch for marking stud edges. Requires a 9V battery (not included).

Product Details

• Product Dimensions: 1.4 x 4 x 8.9 inches
• Shipping Weight: 3.2 ounces (View shipping rates and policies)
• Shipping: Currently, item can be shipped only within the U.S. and to APO/FPO addresses. For APO/FPO shipments, please check with the manufacturer regarding warranty and support issues.
• ASIN: B00019LTXW
• Item model number: 77-110
• Average Customer Review: 1.5 out of 5 stars  See all reviews (32 customer reviews)
• Amazon Best Sellers Rank: #15,998 in Home Improvement (See Top 100 in Home Improvement)
  • #34 in Home Improvement > Power & Hand Tools > Measuring & Layout Tools > Scanners & Testers > Stud Finders

Customer Reviews

Most Helpful Customer Reviews

30 of 30 people found the following review helpful:

3.0 out of 5 stars helps to understand how it works, August 10, 2009

By 

George Smiley - See all my reviews

This review is from: Stanley 77-110 IntelliSensor Stud Sensor (Tools & Home Improvement)

I usually research things before I buy them, but in this case I bought the 77-110 without the usual due diligence. In summary, after testing this thing on a piece of 1/2" drywall and a piece of 1/2" plywood laying across some 2x4's (stud configuration), I have a better idea how to use it. Before the details, I'll bore you with how this thing works (you can skip the next paragraph if you want to just get to the result.

Electronic stud finders work by comparing two things. Everybody knows materials can support a static electric field to a certain degree. Air is better than copper (copper flows electricity but air will prevent electricity from flowing (it insulates). So stud finders compare how well two materials insulate (typically the air-drywall combination versus the stud-drywall combination). The stud finder is basically a metal plate and a capacitor (a thing that stores up an electric charge). The stud finder compares the electrostatic charge stored in the capacitor (the calibration result in the initial air-drywall calibration) to whatever else is there as it rolls along the surface by using the plate. When it detects a difference from the stored charge in the capacitor then it signals the change, first by the bottom red light then the top red light and a beep.

Ok, so if you get the theory then any kind change in the electric charge-storing ability of the material (strictly any change in capacitance property of the material) will trigger a beep and a red light. This is a shortcoming of all electronic stud finders not just the 77-110. How accurate the stud finder is in locating the center of the stud depends on the plate configuration, the geometry of the field it broadcasts and the change detection electronics.

So here are the results of the tests:

(1) on drywall the 77-110 signaled the edge of the stud 1/4" to 3/4" away from the true stud edge when held in the typical way i.e. vertical or parallel with the stud. The pencil point notch on the top of the 77-110 was used to mark the "found" edge,

(2) approaching from the other side produced the same result, so marking both sides and then taking the center-point pretty reliably finds the stud center,

(3) if you hold the 77-110 perpendicular to the stud, i.e. typically parallel to the floor, the 77-110 beeps or light up both red lights about 1/4" into the stud using the pencil notch as the mark point,

(4) lifting the stud finder or moving over a bumpy surface makes it inaccurate and you get false positives, signals a "found edge" but wrong,

(5) it helps to hold your free hand on the wall near the stud finder to eliminate any static charges and keep the AC detector quiet,

(6) if you start out over the stud, the light stays green and will not detect the edge. I assume this means the 77-110 looks only for a drop in capacitance and the air-drywall combination has a higher not lower capacitance than the stud-drywall combination,

(7) the 1/2" plywood had cracks and knots. When this was laid over the studs it gave very unreliable results. I suppose the cracks and knots cause enough of a capacitance change to trigger the calibration value.

(8) placing a smooth thin (1/8") glossy magazine over the plywood made the 77-110 just as accurate in finding the stud as for the smooth drywall,

(9) laying the plywood over the drywall and then using the magazine for a smooth surface produced the same result as the drywall only case,

Bottom line, the 77-110 seems to work as advertised over a nice smooth surface. As advertised it finds the "edge" not the center of the stud. Just remember, it detects the "edge" and you have to calibrate it in a non-stud area, and approach from the other side to find the other "edge" and then take the midpoint.

Over rough or inconsistent surface like the old plywood I used, it was unreliable. I intend to use the 77-110 to locate roof rafters and punching holes in the roof with a nail is not an option. I'll use a combination of old fashion tapping and the 77-110 with a thin magazine.

The reason I gave this product 3 stars, is because I was forced to do all of this experimenting to figure out how it worked. Stanley should do this and include it in the instructions as a tips section..

15 of 16 people found the following review helpful:

1.0 out of 5 stars Piece of garbage, July 11, 2005

By 

Jake (Chicago) - See all my reviews

This review is from: Stanley 77-110 IntelliSensor Stud Sensor (Tools & Home Improvement)

I picked up one of these at a Local Lowes. It was my first time using a stud finder - so I didn't know what to expect. Well I popped in the battery for a test run.

* Ran it across about a dozen walls and it worked perfectly - getting the edges of studs without fail. I tested the results with a thin wire nail at a few places and it was consistently getting the same results

* Today - 3 weeks later - I take it out of my toolbox - and the thing won't measure worth a darn ANYWHERE. I initially thought a wire may be messing up the scans - so I tried it on several walls. Every wall I tested all of the sudden has studs that are six inches wide on edge now.

Total piece of garbage. I am very disappointed in this product b/c I actually had great results with it - but that only lasted for one useage - and it was gently placed in my basement toolbox. I guess they are disposeable.

* One more con against this unit is the 9 volt battery connection. It has the 2 wires that snap onto terminals. It grabbed the batteries so tight that it ripped one of the connectors off my battery. I prefer the ones that slide the 9 - volt battery into place.

Definitely NOT recommended -

Jake

10 of 10 people found the following review helpful:

1.0 out of 5 stars Try a 1 cent nail instead, October 5, 2004

By 

Niall O'Driscoll (San Francisco, CA United States) - See all my reviews
(REAL NAME)   

This review is from: Stanley 77-110 IntelliSensor Stud Sensor (Tools & Home Improvement)

I was too much of a geek to take the advice of the guy at the hardware store, so I bought one of these gizmos instead of a nail. On my walls, at least, this thing is useless. Basically, it finds many more studs than are actually present. So in the end I have to confirm its predictions by driving a thin nail through the wallboard and seeing if it hits wood. There are probably electronic stud finders that work, but this isn't one of them.