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7 votes

Seeing through walls and noninvasive structural integrity metrics

Depending on the region and structure of building the techniques might vary. Below are few suggestions Termite inspection is another popular method to determine the structure integrity of building. ...
Mahendra Gunawardena's user avatar
7 votes
Accepted

Alternatives to laser line?

A few points that don't fit into a comment but could help you: Get a better laser source than a 4 \$ laser diode. "Better" means a laser with higher beam quality. When you look at a laser's ...
OpticalResonator's user avatar
5 votes

What does "redundancy" mean?

Wikipedia says In engineering, redundancy is the duplication of critical components or functions of a system with the intention of increasing reliability of the system, usually in the form of a ...
idkfa's user avatar
  • 1,734
5 votes

Distance sensors with accuracy of 1 mm?

Was looking for other distance solutions, and came across this question. A sensor that I've found works well is the Sharp GP2Y0E02B (digital version) (newer version is the GP2Y0E03). Configuring it ...
asylumax's user avatar
  • 181
4 votes

Calculating pitch, yaw, and roll from mag, acc, and gyro data

From the accelerator sensor data, you can only calculate pitch and roll. The bellow document from Freescale explains with plenty of information what you need: AN3461 - Tilt Sensing Using a Three-Axis ...
Efthymios Kalyviotis's user avatar
4 votes

Difference between PI and PD controller?

PI - Proportional - Integral The output is a combination of how far you are from the goal and the integral of your distance from the goal (total error over time). This means that it will track small ...
Andrew's user avatar
  • 766
4 votes
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How can I detect black spots?

The simplest method will be a multi-step approach. The first step will be a defective product detection, that gathers general data about the product stream and quarantines defective products. On a ...
Mark's user avatar
  • 5,333
4 votes
Accepted

What is the difference between washer and O-ring, what are their advantages of one over the other?

An o-ring usually (but not always) has a round section and is made of a compressible material such as rubber, neoprene, silicon etc. A washer tends to have a square or rectangular section and is ...
Solar Mike's user avatar
  • 15.9k
4 votes

Can a sensor tell the difference between gravity vs. acceleration?

Imagine an accelerometer that is in a box, and held aloft by a rope which is attached to a pulley, balanced by another box of equal mass. You could either: 1) Cut the rope. The box will fall ...
Jonathan R Swift's user avatar
4 votes

Calibrate a sensor using another, already calibrated sensor

The starting point is to recognize that your calibrated sensor is first used to calibrate your light source, and then your calibrated light source is used to measure the response of your second ...
Jeffrey J Weimer's user avatar
3 votes

How to obtain sensor failure probabilities?

Probabilistic Risk Assessment (PRA) is a big deal in the Nuclear industry, basically it is a mathematical approach to quantify how safe/unsafe a power plant is. Without going too deep into PRA it is a ...
willpower2727's user avatar
3 votes

Determining frequency of an ultrasonic transducer

If you're talking about a "bare" transducer (i.e., not a module with its own driver), you can just hook it up to an oscilloscope, hit it with a narrow pulse of voltage, and look for the decaying ...
Dave Tweed's user avatar
  • 6,884
3 votes
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What sensors should be used to analyze vibration of a hard disk?

There are two types of sensors commonly used in hard disks to detect vibration and head crashing. They are: Accelerometer: Accelerometers are used to detect sudden vibrations. Sudden Motion Sensors: ...
Mahendra Gunawardena's user avatar
3 votes

Measuring the road surface quality

While the acoustic analysis idea may* work, I think the accellerometer data would be much easier to analyze. If you are looking for something that can give you better rates of data, try looking into ...
ambitiose_sed_ineptum's user avatar
3 votes
Accepted

Send sensor signals to WiFi network

I would keep the sensors passive as transponders to a house wide rfid radar scanner. Changes in the sensor would change the code on the rfid of the sensor, thus reflecting back a different ...
0tyranny0poverty's user avatar
3 votes
Accepted

Accurately measure the distance from chest to back

The simplest answer would be "a large pair of calipers". In fact, they make such a tool for exactly this task. See http://www.seritex.com/gpm-large-spreading-caliper-rounded-ends-108/ The GPM Large ...
alephzero's user avatar
  • 12.5k
3 votes

What is best sensor & method to measure human height?

Hair is mostly transparent to ultrasonic, so this is still the reliable&convenient approach - any EM spectrum readouts (3D, video, laser) will be completely falsified by hair. You just need a ...
SF.'s user avatar
  • 6,105
3 votes

What is the name and purpose of this Instrumentation / Mechanical fitting

I'd call the blue part the transmitter housing. This usually contains electronics for sensor signal conversion, which converts the sensor (or probe) low level ...
JockeR's user avatar
  • 61
3 votes
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Kalman filter for sensor fusion — what is the advantage?

You can't just "average the two sensors" The acceleration readings are essentially meaningless unless you know their direction, you can't know their direction unless you have the platform ...
TimWescott's user avatar
  • 2,682
3 votes
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Is there an industry consensus standard for storing sensor data?

My experience is there is no particular standards for saving sensor data. Usually one just picks a format that is useful to the task at hand. If, for instance one wants to do post processing analysis ...
Eric S's user avatar
  • 915
3 votes

Calibrate a sensor using another, already calibrated sensor

Plot dat_A against dat_B. Fit a curve to it (linear would be the simplest). Use the curve as a lookup table to lookup sensor A ...
AJN's user avatar
  • 1,124
3 votes

Calibrate a sensor using another, already calibrated sensor

Apart from Jeffrey's excellent analysis I'd like to point out that, assuming that sensor A is calibrated and has a linear response, it seems like sensor has a non linear response. Figure 1: Excel ...
NMech's user avatar
  • 24.4k
2 votes
Accepted

Can Fast Fourier Transform be used to monitor for fault vibrations in a hard disk?

Disclaimer: Although I have studied FFT, I have not applied FFT to a practical application. Therefore I would differ a direct response to someone else. Regardless I would really like to see the end ...
Mahendra Gunawardena's user avatar
2 votes

Pressure sensors with best precision

The reason sensor error is distributed among all those variables is because different applications have drastically different requirements. Let;s take out the errors you can't do anything about: the ...
Ian's user avatar
  • 21
2 votes

Precision measurement of liquid levels

I believe some laser equipment does have the 20µm that you are looking for: Displacement measurement sensors This product for example has a 20µm precision, but it is said that the precision depends ...
Odano Naotake's user avatar
2 votes

What is Radial and Thickness Mode Vibration in a Piezo Electric Ceramic Disc Transducer?

Texas Instruments has extensive material on this Piezo Electric disc for applications of measurements fluid level. You can search their website for STEMINC and you will see two discs used on Thickness ...
Matthew's user avatar
  • 21
2 votes

Low cost, moderately accurate water depth measurement

Measuring water in open channels is a basic element of water conservation. With the increasing demand for improved water management techniques, there is a serious need for low-cost and accurate water-...
Kyla peter's user avatar
2 votes

How to measure height of water

How about using a Capacitive Fluid Level Sensor from Molex. The sensing element can be affixed outside of the tank. Here is an image of the sensing element affixed outside of the a container. . ...
Mahendra Gunawardena's user avatar
2 votes

How do I sense reflective tape such as on a spinning wheel?

The "laser device" you're looking for is called a Laser Tachometer, though other illumination sources will work. I have had good success with devices from Monarch Instruments. Specifically the ROS-P ...
DLS3141's user avatar
  • 2,145
2 votes
Accepted

How to determine / control if a conveyor belt runs straight?

Alignment Monitoring There are many switch systems that can be mounted to the frame that will detect when a conveyor is beyond the acceptable limits of alignment. A google of "Conveyor Belt ...
Dopeybob435's user avatar

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