Analytical Balance

Creator: EnabrinTain Status: Research Born On: 11:15, 22 January 2013 (CST) Last Updated: 13:20, 12 June 2013 (CDT)

Overview

This is where I'm hanging research for building an Analytical Balance. I'd prefer to drive it with an arduino, maybe even make a shield for it.

Analytical Balance Links

• Hackaday!
  • Strain Guage based weight sensor
    • Justin says he used the wrong glue though ("you are supposed to use cyanoacrylate glue (super glue) the epoxy is horrible and transfers load incorrectly")
    • He also says that a better amp to use would have been ADS1231

Wheatstone bridge

Magnetic Force Restoration

1. Simplifying the Electronic Balance Load Cell
2. PDF
3. SCIENTECH BALANCES
4. Solenoid Coil Electromagnetic Force Calculator

Capacitive Sensors

1. Capacitive Displacement Sensors
2. Wikipedia: Capacitive sensing
3. Displacement, Location, or Position Sensors

Physics

1. Levers
2. Instrumentation amplifier
3. DESIGNER'S GUIDE TO INSTRUMENTATION AMPLIFIERS

Patents

1. Patent from 1971 (opamps!)
2. Patent from 1979
3. OpAmp tutorial
4. Amplifier Circuits
5. The OpAmp Bible

Equipment/Acquisition

• 20 Neodymium Magnets 15 x 10 x 5 mm Ring N48 (ebay: $35.78:arrived)
• 20 Neodymium rod magnet 3mm x 10mm N35 (ebay-uk: $8.25:arrived)
• Calibration weight set (100g to 10 mg) (ebay: $17:arrived)

Calibration Weight Calibration (yo dawg)

From the balance we used to verify the weights' mass: Calibration info from the balance just a few days before:

Load Test (within tolerance)

Actual Weight	Reading
0.0000 g	0.0000 g
0.0200 g	0.0200 g
0.1000 g	0.1005 g
2.0000 g	2.0006 g
50.0000 g	50.0000 g
100.0000 g	99.9998 g
150.0000 g	149.9986 g
200.0000 g	200.0003 g
210.0000 g	209.9999 g

Weights

Stated Weight	Reading
100 g	100.0045 g
50 g	50.0025 g
20 g	20.0040 g
20 g	20.0000 g
10 g	10.0000 g
5 g	5.0035 g
2 g	2.0157 g
2 g	2.0159 g
1 g	0.9985 g
0.500 g	0.5280 g
0.200 g	0.2012 g
0.200 g	0.1992 g
0.100 g	0.1186 g
0.050 g	0.0510 g
0.020 g	0.0238 g
0.020 g	0.0230 g
0.010 g	0.0089 g