Load Cells - PowerPoint PPT Presentation

Loading...

PPT – Load Cells PowerPoint presentation | free to download - id: 415558-OTRlY



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Load Cells

Description:

Load Cells Erwin Kohler Definition A load cell is a force transducer that converts force or weight into an electrical signal The strain gage is the heart of a load ... – PowerPoint PPT presentation

Number of Views:26
Avg rating:3.0/5.0
Slides: 13
Provided by: ErwinK1
Learn more at: http://dankuchma.com
Category:
Tags: cell | cells | load

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Load Cells


1
Load Cells
  • Erwin Kohler

2
Definition
  • A load cell is a force transducer that converts
    force or weight into an electrical signal
  • The strain gage is the heart of a load cell

3
Factors Affecting Load Cells
  • Manufacturer
  • The precise positioning of the gage
  • Mounting procedure
  • Materials used
  • User
  • Impact and hysteresis
  • Test modes tension/compression
  • Off-axis loads

4
Classification and Application
  • Single point

Bending beam
Platform scales1-1000 Kg
Low profile load and pallet scales5-500 Kg
Shear beam
Low profile load and pallet scales500-5000 Kg
5
Compression Load Cells
  • Preferred by testing engineers
  • Higher output
  • Better fatigue life
  • Better resistance to extraneous loads
  • Greater stiffness
  • Overload protection


6
Load Cells in Engineering Testing
Force versus deflection. Fatigue tests
Adhesive and paints peel force
7
Load Cells Errors
  • Impacts and hysteresis
  • Metal retains a history of its previous loadings
  • When the loading is properly done, then the curve
    will return to zero
  • If, by mistake, 80 of load is applied by impact
    and then returned to 60, then the load cell
    would be operating on a minor hysteresis loop
  • DONT IMPACT LOAD CELLS

8
Load Cells Errors
  • Test modes and calibration
  • Load cells are routinely conditioned in one mode
    (either tension or compression) and then
    calibrated
  • Determine test mode needed
  • Some cells can be operated in both modes without
    reconditioning, but result in non-return to zero
    after looping through both modes
  • Special fatigue load cells
  • Sharp corners and edges are polished to avoid
    crack propagation
  • Longer service life including fully reversed,
    full capacity loading cycles

9
Load Cells Errors
  • On-axis loading
  • All on-axis loading generate some level of
    off-axis extraneous components because of load
    carrying members causes friction that transmits
    side load
  • Avoid flat-to-flat load, because it is impossible
    to maintain two surfaces parallel enough to
    guarantee that the force will end up being
    centered
  • Compression cells have load buttons

Load button - 4 for 10,000 lbf - 6 for
50,000 lbf -12 for 200,000 lbf
3/8 off center with 5 degrees misalignment
causes large moment
10
Load Cells Errors
  • Nonrepeatibility
  • Function of the resolution and stability of the
    signal conditioning electronics
  • Load cells typically have nonrepeatibility which
    is better than the load frames, fixtures and
    electronics used to measure it.

11
Reference Prices
LOAD SENSORS
.
Low Cost Compact Compression Load Cells
399
.
Subminiature Compression Load Cells - High
Stability
395
.
Miniature Load Beams
599
.
Miniature Compact Tension/Compression Load
Cells - High Output
565
.
Industrial Flat Disc Tension/Compression Load
Cells - Stiff Shear Design
899
ACCESSORIES
.
Compression Load Button Adapters for Load Cells
60
.
Tension Pull Plates for Load Cells
150
12
Manufacturers
  • Measurement specialists www.measurespec.com
  • Entran sensors and electronics www.entran.com
  • Tedea Huntleighwww.aboutloadcells.com
  • Interface www.interfaceforce.com
About PowerShow.com