Need suggestions for accurate alternatives to FSR

Thread Starter

Daedalus357

Joined Sep 4, 2017
1
I am creating a bottle weight measurement system. The bottle must be in a hanging state so that it is easy for the customer to replace, thus I cannot use a conventional scale for this application. I have tried using a Force Sensitive Resistor (FSR), however the readings will vary by nearly 100 points each time I remove and reconnect the bottle (even without liquid!).

I am looking for cheap, but accurate alternatives to a FSR. I have tried looking into Load Cells, however they are on the scale of over $100, even for smaller newton ratings.

Specifically I need something similar to this:

https://www.adafruit.com/product/166

edit: forgot to mention that I need to be able to ship to Japan... I'm not in the US or UK
 

BR-549

Joined Sep 22, 2013
4,928
" The bottle must be in a hanging state so that it is easy for the customer to replace, thus I cannot use a conventional scale for this application. "

What does that mean?

What is the size and weight of bottle.......need much more details. Photos...schematics....etc.
 

DickCappels

Joined Aug 21, 2008
10,180
As previously pointed out on this forum the load cells used in small scales like the gram scale I have a gram scale for the kitchen that cost only $10 cannot be very expensive. Perhaps buying and taking apart bathroom and gram scales will lead you to the maker of inexpensive sensosrs like the one at the link below.

https://www.sparkfun.com/products/10245
 

Raymond Genovese

Joined Mar 5, 2016
1,653
I am creating a bottle weight measurement system. The bottle must be in a hanging state so that it is easy for the customer to replace, thus I cannot use a conventional scale for this application. I have tried using a Force Sensitive Resistor (FSR), however the readings will vary by nearly 100 points each time I remove and reconnect the bottle (even without liquid!).

I am looking for cheap, but accurate alternatives to a FSR. I have tried looking into Load Cells, however they are on the scale of over $100, even for smaller newton ratings.

Specifically I need something similar to this:

https://www.adafruit.com/product/166

edit: forgot to mention that I need to be able to ship to Japan... I'm not in the US or UK
You have given us so little information, it is tough to know how to respond and I hope that you will come back and re-engage. For example, what is the weight and accuracy that you need?

1. View weight as present or absent (I know you probably don't want that) with a simple micro-switch

2. As mentioned, load cells can be had for much less than $100. Here is one with an HX-711 for $13

3. Go analog with a Push/Pull guage

4. Build your load cell/strain guage
 

Reloadron

Joined Jan 15, 2015
7,517
Unfortunately you do not mention a weight you wish to measure? There are literally dozens of load cells out there using tension or compression, I believe you want tension. Most are very inexpensive and from China.Finally,as mentioned, you do not mention an uncertainty (accuracy) you need. There are literally dozens of load cells out there from Amazon and other suppliers as well as signal conditioners to be used with those load cells. I would think there are plenty of distributors in Japan. Provide some specifications and I am sure you will get some workable results.

Ron
 

BR-549

Joined Sep 22, 2013
4,928
And there could be other solutions. Using light or shadow.......maybe the level of the product could be used as weight.
 
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