Load Cell Sensor - 50kg

Load Cell Sensor – 50kg

We've sourced this high quality sensor as a lower cost variant to our Sparkfun 50Kg Load Sensor sourced part.

The sensor can be used by itself, or as a team!:

•  Full bridge measurement range of a sensor range: 50kg.
• Use two full-bridge sensors and the measurement range is: 50kgx2 = 100kg
• Use four full-bridge sensors and the measurement range is: 50kgx4 = 200kg

50Kg Load Sensor Specifications:

• Capacity: 40-50 kg
• Comprehensive Error: 0.1 %FS
• Output Sensitivity: 1.0 mv/V ±15%
• Nonlinearity: 0.05  %FS
• Repeatability: 0.05 %FS
• Hysteresis: 0.05 %FS
• Creep: 0.01 (1min)%FS
• Zero Drift: 0.01 (1min)%FS
• Temp. Effect on Zero: 0.3 %FS/10 ℃
• Temp. Effect on Output: 0.1 %FS/10℃
• Zero Output: ±0.1 mV/V
• Input Resistance: 1000 ±20 Ω
• Output Resistance: 1000 ±20 Ω
• Insulation Resistance: ≥2000 MΩ
• Excitation Voltage: ≤10 V
• Operation Temp. Range: -10 ~ +50 ℃
• Overload Capacity: 150 %FS

The NerdKids took a cheap digital scale and hooked it up to an amplifier and a microcontroller. This video outlines them taking apart the scale, wiring it to the amplifier as well as coding. There is also a great overview of the concepts behind strain gauges and Wheatstone bridges. Check out the demo of two live scale apps written in Python near the end of the video.

Note: there’s a lot going on in this project, from the cantilever bending to the bridge noise cancellation to the PC graphics code. It’s a complicated one, so take it slow.

Load Cell Source Code:

You can download the Weigh Scale Source Code. (Start with one of the projects included with the kit, and modify the Makefile to reference this file.) You can also see the source code for the PC-side software, live scale graph and also, live can counter.