Calibrating Machine Deflection for Elite Series Equipment

Summary

Although Humboldt Testing Equipment is manufactured to precise tolerances, there will always be a small amount of play (or deflection) as the equipment is put under various loads. Accordingly, that deflection can vary as different stress values are placed on the equipment during testing.

Procedure

To calculate the mechanical deflection:

1. Install the Consolidometer assembly including the upper and lower porestones, and filter paper if used in the actual test. The calibration disk will fit inside the cutting ring in place of a test sample.
2. From the face of the machine apply a seating load 2 LBF (0.009 kPa).
3. Note the current displacement value once the 2 LBF (0.009 kPa) target is reached.
4. Now apply the first load of the loading sequence.
5. The deflection for the first load is the current displacement once the target load is reached - step 2 displacement.
6. Note the displacement.
7. Apply the next load of the load sequence.
8. Once the load has been achieved the deflection for the current load is the current displacement - step 5 displacement.
9. Step 5 - 7 needs to be applied to all loads in the loading sequence.

Fig. 1: Calibration disk loaded into Consolidometer on top of pore stone and filter paper.

Fig. 2: Fully assembled Consolidometer with calibration disk inserted in place of test sample.