I am looking to build a solids particle flowmeter that can tell me how much weight of the solids have been dispelled over the time of that batch period. By looking at similar products online by Siemens (link below) the flowmeter consists of a plate in which the solids fall on that has a load sensor to measure the imposed force. There is also an “accompanying integrator” that measures flow rate. The integrator would be an RPM sensor using hall effect and magnets OR modify a liquid flow meter to use for solid particles.
The load sensor I have is SEN-10245 (link below). I know that I need to order a voltage amplifier in order for the Arduino to detect the small changes in voltage BUT do I also need to order another load sensor to act as a bridge to carry half the voltage (like in the video link below)? Looking at forum posts and other pages online they use two load sensors but I want to use one according to my planned design (picture below).
I want to get an online order placed in the upcoming days and so I am asking if I need another load sensor (identical to the one I have) in order to accomplish my goal.
If anyone has any experience making a solids flowmeter / load sensor please help me out!
Siemens link: http://www.automation.siemens.com/sc-static/catalogs/catalog/wt/WT10/en/WT10_en_kap06.pdf
My Load Sensor: Load Sensor - 50kg (Generic) - SEN-10245 - SparkFun Electronics
Video link of two load sensors: Application Example of using the 50kg Load Sensor SEN-10245 - YouTube
You can use two resistors (well matched -- probably need to include a potentiometer somewhere to balance it out) to create the other half of the bridge but the disadvantage to that is that you don't get as much sensitivity as two half bridges would provide. See the "Half Bridge Strain Gauge Circuit" for an explanation of how this would be done. Just read the whole page, really 
You're going to need an amplifier as well; these gauges only show a few millivolts of variance when stressed. You can use an InAmp as in the video but then you're stuck with the Arduino's 10 bit ADC. A better way to go is to grab an HX711 module off eBay (or somewhere) and you'll get more precision than you'll ever need.
Hi, use the "Search the Arduino Forum" window above right and search for load cell.
An number of threads have been discussed on this forum about amplifying load cell outputs to get arduino input voltages.
Tom......... 
So does the HX711 require a 4 wire load cell? According to the wiki (Weight_Sensor_Module_V1-DFRobot) it does. Mine is a 3 wire one but the code seems really easy which is a huge plus for a newbie coder like myself.
I am willing to take the 10$ hit on the load cell I currently have and buy a new 4 wired one with a higher weight capacity. I think the required weight for my project will be more than 50 kg which is the max that my current load cell can handle.
Do you know of any sites that sell the HX711 and a 100 kg load cell together? I am having trouble finding them on one website together and I would like to order from just one place.
There is also an “accompanying integrator” that measures flow rate. The integrator would be an RPM sensor using hall effect and magnets OR modify a liquid flow meter to use for solid particles.
Is the mechanical accompanying integrator needed? It seems to me that the integration could be done using the force signal and time in your code. From what I could see, the Siemens integrators are electronic devices, so perhaps the Arduino could be your integrator.
scotthetland:
So does the HX711 require a 4 wire load cell? According to the wiki (Weight_Sensor_Module_V1-DFRobot) it does. Mine is a 3 wire one but the code seems really easy which is a huge plus for a newbie coder like myself.
With the previously-mentioned resistors building the other half of the bridge with your present strain gauge you would have "four wires". Two for power (excite +, excite -) and then the sense wire from the strain gauge and the sense wire from your resistor voltage divider.
I'd generally expect a four wire load cell to be more sensitive, but really can't say if that would be important for your application or not. Just one of those things you're going to have to test out.
