Abstract: A multiple sensitivity stud sensing device for determining a location of objects behind a wall lining has a housing with a surface for moving over the wall lining. Within the housing are a capacitive sensor with first and second capacitances provided adjacent the surface and control circuitry. The control circuitry includes a detecting circuit connected to the sensor for providing a detection signal related to an imbalance between the first and second capacitances, a processor for receiving the detection signals signal and providing a display signal. A display is provided on the housing for indicating a location of an object behind the wall lining. The processor compares the detection signal to stored predetermined threshold values of detection signals associated with different wall lining thickness and displays a thickness value to the user.

Abstract: A distance measuring device includes a transmitter for transmitting an acoustic signal at a distant object, an acoustic signal receiver for receiving a reflected acoustic signal reflected from the distant object, a temperature sensor detecting air temperature, a humidity sensor detecting air humidity, an amplifier amplifying the reflected acoustic signal, a comparator coupled to the amplifier comparing the amplified reflected acoustic signal with a reference and generating a comparator output when the level of the amplified reflected acoustic signal exceeds the reference, a gain controller increasing the gain from transmitting an acoustic signal until the comparator output is generated, a threshold generator providing the reference to the comparator and decreasing the reference at an exponential rate from transmitting the acoustic signal until the comparator output is generated, and a controller determining use of only the air temperature, velocity of the acoustic signal, and distance traveled from transmitti

Abstract: A multiple sensitivity stud sensing device for determining a location of objects behind a wall lining has a housing with a surface for moving over the wall lining. Within the housing are a capacitive sensor with first and second capacitances provided adjacent the surface and control circuitry. The control circuitry includes a detecting circuit connected to the sensor for providing a detection signal related to an imbalance between the first and second capacitances, a comparator having a reference signal for providing a comparator signal related to a difference between the detection signal and the reference signal, and a controller for receiving the comparator signal and providing a display signal. A display is provided on the housing for indicating a location of an object behind the wall lining. An input device is provided on the housing so that a user of the device can select a value for the reference signal.

Abstract: A portable device for selectively locating a wooden object, a metal object or a live AC wire positioned behind a wall surface covering when the device is moved along a wall surface is disclosed. Wood is detected by changes in effective dielectric constant, metal is detected by changes in magnetic reluctance and a live wire by detecting modulation signals at mains frequency. The device is controlled by a microcontroller to provide discriminating visual and audible signals when each of the kinds of objects are proximate the device.