Hot answers tagged

17

Pitch, roll and yaw are defined as the rotation around X, Y and Z axis. Below as a picture to illustrate the definition. In a previous project I used a ADXL345 Accelerometer from Analog Devices to calculate roll and pitch. Below are the equations used to calculated roll and pitch. I have made some of source code available for public use. accelerationX = (...


14

You could just hit a pendulum and measure the angle to which it swings. I have found that three liter soda bottles filled with water and hanging from a rope are good for hitting. Knowing the weight of the bottle, a little trig will give the energy, from which you can get the force. Edit: If the transfer of energy from fist to target happens through a short ...


13

Technology used in depth finder, in marine application is mostly like is the best to measure the water from the top. To measure water level from the bottom of tank one could use a piezo electric ceramic transducer combined with an Analog Front End (AFE) and a micro-controller to measure water level. The diagram below best explains the configuration. You ...


12

So my longer answer below assumes that the board will undergo acceleration and during this time you still need to be able to measure your pitch, roll and yaw within a short amount of time. If the board will be stationary for all measurements then Mahendra Gunawardena's answer will work perfectly for you. If this is going into a device like a segway or model ...


10

I think that an impact force sensor is what you're looking for. I'm not sure how expensive the linked sensors are so you could also use an acceleration sensor and do a little math. The second option is likely to be less accurate but I suspect that it will also be significantly less expensive! I know you said that you didn't want the complete system design ...


10

I think what you want is a piezoelectric pressure sensor. You might be able to steal one from an old bathroom scale, but the sensors in a scale may only be good up to ~100 lbs of force. These piezoelectric transducers convert applied pressure to a small voltage across the two leads. This pressure can be converted to force by measuring the surface ...


7

I'm going to offer a slightly less helpful answer by poking holes in the answers of others to explain why they aren't ideal, then offering an incomplete, poorly thought through answer of my own. The majority of answers here suffer from one of three stumbling blocks: they require unnecessarily large jigs to be feasible with complexities which make them ...


7

This information you have, in theory, allows complete reconstruction of location and orientation of the bike along the entire path. This is basically what is referred to as inertial navigation. However, the problem in real life is that there will be some error on all the signals. Since determining location and orientation require integrating the signals ...


7

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. A handheld radar scanner from DeWalt might also do the job as describe here. Depending on the type of pipes a metal detector might be another good option. Non-...


6

Buy a depth finder! As @SF pointed out, you can use an ultrasonic device to measure the depth of the water. These devices work by sending out an acoustic impulse and recording the return signals. The acoustic impulse reflects off of any density boundaries in the medium. By measuring the time for the signal to come back the distance from the transducer ...


6

Conductive foam will change it resistance when compressed, so it makes a good, cheap force sensor, as long as you have a system to make many measurements in quick succession and remember the one with the least resistance. Depending on the force you want to measure, you can use several layers above each other, and because you can cut it into any shape, you'...


6

There are many different sensors that can be placed on a bridge to help monitor its condition. After the I-35 bridge collapse, this area has seen a lot of publicity. Most of these sensors were previously available, but the need wasn't as apparent to the public. Sensors Accelerometers Strain Gauges Displacement Transducers Level Sensing Stations (Tilt ...


6

Answering the question: What are possible types of low cost sensors I can use? There are several types of sensors that can provide millimeter level accuracy. "Low cost" is a very relative term, so you'll need to do some shopping around based on your specific budget. Optical sensors- Included here are those of the type you listed, though it's a very ...


6

Yes To answer your specific question, yes, you can use an ultrasonic sensor to measure fluid level. Mahendra's answer describes that. You mentioned that you feel that an ultrasonic sensor is the best solution, but I wanted to add make sure that you were aware of some of the other methods that are used to measure fluid levels. Measuring Techniques This list ...


6

Since you seem to not be too familiar with control systems, electronics, and wiring things, I recommend a simple threshold detector that controls a relay. The relay then switches the heating element on or off. Unless the IR thermometer has a output signal for this purpose, it won't be useful as the sensing element. However, there are various devices that ...


6

Look at it this way: A simple compass will detect from zero to about 0.1 Hz your AM radio detects around a MHz your cellphone around a few GHz or so Radar systems anywhere from 100kHz to 1 THz Special materials can handle parts of the range from 10 microns to 0.1 micron (which includes the visible) Special crystals & other things can detect hard ...


5

I agree 100% with Jeff, the advantage of this is that you could build it for cheap, very, very solid. The height it swings to will give you the energy with the formula $E=mgh$ where E=energy in Joules, m=mass in kg, g=9.81m/s^2, h=height difference in m This will be the total amount of energy transferred to the target. Unfortunately, this amount of ...


5

There is an excellent white paper from piezotechnologies.com which is probably worth a read if you are new to working with piezoelectric devices. Quoting from the section on resonance frequencies: If an AC voltage is applied to a piezoceramic disc with a diameter several times its thickness, two series of resonances may be observed. The resonance at the ...


5

You are combining two concepts. A sensor is any device that responds to a desired signal in some manner to produce an output that is used to detect the presence of the desired signal or to allow some desired attribute of the signal to be measured - such as its amplitude, frequency, rate of change, relative phase, etc. Even colour, temperature, dimensions, ...


4

Radial: Oscillatory waveform is between edge and centre. Thickness: Oscillation is across disc faces so will be higher frequency all else being equal. Axial and thickness are probably equivalent terms. Interestingly, while the relationship does not have to be this close Your thickness mode disc resonates at 1 MHz and is 2.1mm thick. Your radial mode ...


4

The problem with quantifying impact force is the short duration of what is usually a 'peaky' pulse. Bathroom scales are usually damped to give a steady reading of a static force and won't capture transient peaks. Ballistic pendulums also have problems - some of which have been discussed. However, for training young fighters, I'd suggest that you don't ...


4

Here is a really cheap and cheerful way of showing the size of an impact. Take 2 boards of plywood, put a large compression spring between one and the other board so the spring is sandwiched but removable by at least one of the boards like an "H". Bolt this to a wall."H|" Get set size balls of playdo (kids putty) place on of these inside the spring (...


4

A strain guage attached to a target would be helpful. Unlike piezzo, they are very durable against impact type force (piezzo crystals tend to shatter when the pressure is applied rapidly). They can be attached to pretty much arbitrary "board" which yields very little, so unlike pendulum types they will not falsify the results with force applied slower, or ...


4

These are few suggestions to develop the system I suggest using a polymeric bladder type approach used in Passage Occupancy Detection Systems in automotive industry. This patent describes the automotive application. The bladder system would be part of the focus mitt, which include a MEMS base differential pressure sensor. When impact force will be detected ...


4

I can say using accelerometers to detect displacement won't work. These devices have so much of inherent noise that discerning very slow acceleration from remaining immobile is about impossible. You won't be able to detect acceleration of order of 0.1 mm/s2 and it takes just a several seconds at such acceleration to exceed your 5mm. You'd have a hard time ...


4

Hand-held sensors measuring multiple properties may require more than one type of sensor element; it's important to know what exactly you need to measure. There is no one property (or fixed set of properties) that defines "water quality" though some (including the two you mention, pH and TDS) are more commonly used than others. In the case of pH and TDS, ...


4

It is likely that the noise of the motorcycle is causing the sensor to activate. This listing of the advantages and disadvantages of ultrasonic sensors lists one of the disadvantages as: While ultrasonics exhibit good immunity to background noise, these sensors are still likely to falsely respond to some loud noises, like the hissing sound produced by ...


4

If you want this automated, probably Rachet's solution is better; for a more low-tech approach for periodic manual testing, a wide, flat weight on a rope will work; lower it below water surface, let it rest on top of the sediment; the moment the rope goes loose, you've touched the sediment surface. For a more hi-tech solution, an ultrasound distance sensor ...


4

You can put a rod with a blades on the bottom rotate it along the bottom. when the resistance is high then the sediment has reached above the blades and it is time to clean the tank.


4

First you need a part that exceeds its fatigue limit under expected stresses because you need slow coalescence of cracks occurring uniformly in the measured area, not a local defect which might occur outside the sensor placement and resistant to modelling based on measurements from other pieces of the part. Steel/titanium etc parts stressed below their ...


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