Help with density measuring device

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Discussion Overview

The discussion revolves around the development of a device to measure the density of multilayer objects, specifically in the context of a school project. Participants explore various methods and sensors to achieve accurate measurements, considering both theoretical and practical aspects of the design.

Discussion Character

  • Exploratory
  • Technical explanation
  • Homework-related

Main Points Raised

  • One participant proposes measuring the axial force exerted while pushing a device into a multilayer object to determine density.
  • Another participant questions the specifics of what density is being measured, suggesting the need to clarify whether overall density, individual layer density, or layer density per unit length is desired.
  • A suggestion is made to record the pressure needed to advance a pin at a fixed rate to obtain a depth profile of resistance, with various questions about the layered material and pin design raised.
  • A participant mentions redesigning their project to monitor the acceleration of a hand drill during drilling, considering the use of an accelerometer or pressure sensor for measurement.
  • Another participant challenges the need for complex measurements by suggesting that visual observation of drill penetration could suffice.

Areas of Agreement / Disagreement

Participants express differing views on the best approach to measuring density, with no consensus on the specific methods or sensors to use. The discussion remains unresolved regarding the optimal design and measurement techniques.

Contextual Notes

Participants highlight various assumptions about the properties of the multilayer materials, the design of the measuring device, and the potential effects of friction and material behavior during penetration, which remain unaddressed.

stregoi
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Hi every one i hope someone can give me an idea how to achieve that. I am working for at school project, where i am trying to build a device that measure density of a multilayer object/environment. I am thinking to achieve that by measuring the axial force exerced while pushig the device inside the multilayer object.
But how exactly to do that, and what sensors i have to use - i can't really figure that out.
any one can help ?
 

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Welcome to PF;
Isn't it part of the project that you are supposed to figure that stuff out?
You should start by being specific about what you want to measure ... do you want an overall density (i.e. total mass divided by total volume?) or do you want to know the density of the layers individually or do you just want something like a layer density (number of layers per unit length) or something else?
The you need to think about how the kind of density you want to measure affects the action you propose to use to measure it ... how do the layers resist the rod pushing through them?

YOu should also be prepared to abandon approaches that don't work well, or where you have too much trouble getting them to work right.
 
If you push the pin at a fixed rate while recording the pressure needed to advance you will get a depth profile of resistance to penetration of the material.
What is the layered material?
What is the dimension of the problem, pin diameter? and layer thickness?
Do the layers always increase in “density” with depth, or are some less dense than earlier ones?
What shape is the end of the pin; flat, spherical or pointed?
Will the pin push material on the flat end?
How will you avoid friction between the side of the pin and the material?
Will the layers flow or fold back again after penetration?
Might you be better using a ball on a thinner pin to avoid friction?
 
Hey guys thanks a lot for the answer, really appreciate it .. i was thinking about my project and i redesignet it, to be more specific ( hopefully making it easy for my self to achieve )
I am trying to monitor, the accelerating of a handdrill, while drilling ( and thus being able to register the slip when the drill go through the other edge of the wood panel ).
I was thinking about using an accelerometer as a sensor to achieve that ? or a pressure sensor ? but is it precise enough to do the job, any idea og suggestion how to achieve that the best way ?.
 
sounds like something you could do ... but you still suffer from lack of detail: what do you want to achieve? I.e. why not just detect the drill penetration by looking at it, you know, the normal way?
 

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