Step-by-Step Guide: Performing a Staircase Test
Master the Up-and-Down method for determining impact failure weight with this practical SOP.
The "Staircase" Logic
Unlike simple tensile testing, Impact Testing is statistical. You can't just test one sample. You need to find the "tipping point" where 50% of samples fail. Here is how to do it with the MLB-01.
Equipment Setup
Required:
• MLB-01 Impact Tester
• Air Source (0.4~0.6 MPa) for clamps
• At least 30 identical film samples (>150mm x 150mm)
Step-by-Step Procedure
Step 1: Estimate Initial Mass (Mo)
Guess a weight where the film might break. Load this weight onto the dart.
Step 2: Clamp Sample
Place the film on the lower clamp. Step on the foot switch to activate the pneumatic cylinders. Ensure the film is flat and taut.
Step 3: Drop & Observe
Press the "Test" button. The dart falls.
• Check for Failure: A "Failure" is any visible crack or hole that lets light through. Even a tiny pinhole counts!
Step 4: Input Result
• If it broke: Press "Yes" (Broken). The system will prompt you to Remove a weight increment (Delta M).
• If it survived: Press "No" (Not Broken). The system will prompt you to Add a weight increment (Delta M).
Step 5: Repeat
Load a new sample. Adjust the weight as instructed. Drop again.
Repeat this for 20-30 drops.
Step 6: Automatic Calculation
Once the criteria are met (usually N=10 failures or non-failures), the MLB-01 prints the final result: Impact Failure Mass (g) and Impact Energy (J).
