1. Readout units and the calibration of loadcells.
Date : 31 July 2017
Sipho Dlamini
Test and Measurement Conference 2017

2. CONTENTS Introduction Readout units and force calibration of loadcells
Force laboratory at NMISA
Force machines
Force transducers (loadcells)
Measuring amplifiers (readout units)
Readout units and force calibration of loadcells
Calibration of readout units
Conclusions

3. The Force laboratory at NMISA
National measurements institutes (NMIs) of countries around the world are usually tasked with maintenance of measurements systems and standards.
The force laboratory at NMISA is tasked with the maintenance and dissemination of the standard unit of force (Newton)
Maintaining and dissemination of force standard
Capability to generate force
Capability to measure the force generated accurately
Calibration

4. Capability to generate force
NET DOWNWARD VERTICAL FORCE

5. Capability to measure the force generated accurately

6. Calibration

8. The readout unit should not pick up noise from outside sources
The readout must not add noise to the signal and, if possible should reduce or remove any noise that is already in the signal from the loadcell.
The readout unit should not pick up noise from outside sources
Performance should not be affected by ambient temperature for those readout units that must operate in extreme environment
The performance of a readout unit must be stable over time

9. Connection cables

10. Calibration of readout unit units
The performance of a readout unit must be stable over time

11. Calibration of readout unit units (Stability)

12. Calibration of readout unit units (Stability)

13. Performance should not be affected by ambient temperature for those readout units that must operate in extreme environment

14. Calibration of readout unit units (cable configuration)

15. Conclusions For force measurements
Stability of readout units should be monitored
Readouts are generally stable over long periods of time
Connection cables can influence calibration measurements
6 wire configuration vs 4 wire configuration

16. Thank you