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Topic: Measuring G-Forces, range of magnitude 20 - 80 (Read 762 times) previous topic - next topic

Cor_Jac

Good day all
I need to measure the G-Forces experienced by a product when dropped, I was wondering if I could build up something with the products sold by Arduino ?  I have one handicap though, I wouldn't know how to wire things up... or to select the correct components.  Has anyone build something like this yet ? or, be able to guide me through this project ?
Ideally the results would be either stored to a mini SD card, or a cable to an USB port would be great too.
Quite a few test will need to be done, so I will need to build something with suitable components.
How would I calibrate or verify this unit to ensure that the readings are fairly accurate ?

Thank you for your support.

raschemmel

#1
Mar 21, 2014, 05:13 am Last Edit: Mar 21, 2014, 03:51 pm by raschemmel Reason: 1
Quote
Has anyone build something like this yet ? or, be able to guide me through this project ?]  Has anyone build something like this yet ? or, be able to guide me through this project ?

Show us that you taken the time to at least research it on google first before  coming here and asking us to do all the work.
Arduino UNOs, Pro-Minis, ATMega328, ATtiny85, LCDs, MCP4162, keypads,<br />DS18B20s,74c922,nRF24L01, RS232, SD card, RC fixed wing, quadcopter

Caltoa

#2
Mar 21, 2014, 02:45 pm Last Edit: Mar 21, 2014, 02:50 pm by Caltoa Reason: 1
Measuring impact g-forces is an advanced project.
The Arduino might not be suitable for an industrial level, but as a hobby project you can certainly measure the impact.

How many axis of g-forces do you want to measure ?
Sparkfun sell a simple 250g sensor: https://www.sparkfun.com/products/9332
But that is only single axis.

What sample rate do you want ?
At 100Hz the Arduino is able to do some calcuations and write it the an SD card or send it to an computer.
A sample rate of 1kHz needs optimized software, and continuous recording can be a problem.

The smaller the Arduino board, the more it can withstand mechanical shocks.
Many Arduino boards have a crystal for the clock, those can break. A mechanical resonater is better, and using the internal clock circuit is completely shock-proof.
A maximum is 80g is not a lot, so I think that any official Arduino board (not a cheap clone) should last for a long time.

My suggestion is to use one of the smaller Arduino boards like the Arduino Nano or Micro. Buy that sensor from Sparkfun. Send all the data via usb to the computer, and see for yourself if that is good enough for you. The Arduino is all about trying and learning and having fun.

There are many other ways to measure it. For example a g-force sensor with a frequency output connected to the audio input of a computer. Or a usb capture device, something special for transient recordings, or a common usb oscilloscope.

raschemmel

Quote
The smaller the Arduino board, the more it can withstand mechanical shocks.

The expensive data acquisition systems (like HBM equipment) usually have a BNC connector (one for each axis) and the cables can be 25 ft long (or more I think) . The ones I used were about 3 meters long. The input section of the system had instrumentation amps for each axis. I couldn't find anything in the sparkfun ADXL193 datasheet regarding maximum cable length so I think if you
at least keep your accelerometer cables to less than 3 meters you should be fine.
Arduino UNOs, Pro-Minis, ATMega328, ATtiny85, LCDs, MCP4162, keypads,<br />DS18B20s,74c922,nRF24L01, RS232, SD card, RC fixed wing, quadcopter

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