The Spencer Impact method is based on ASTM D 3420. An attachment to the Elmendorf Tear Tester is mounted on the top of the instrument and measures the puncture impact resistance of a plastic film sheet or other related sheet-like material. The fixture consists of a probe mounted onto the end of the Elmendorf pendulum and an air-operated clamp used to secure the film sample. The unit measures the resistance to impact/puncture as the probe penetrates a sheet of plastic film. Both Elmendorf Tear and Spencer Impact measurements can be performed on one instrument.

The Testing Machines Inc Spencer Impact fixture consists of an air-operated clamping ring with a diameter of 89.0 +/- 0.5 mm. The puncture impact arm has a radius of 12.7mm and a diameter of 19.0 mm. Measurement ranges include 200, 400, 800, 1600, 3200 and 6400 gf. Spencer Impact Attachment meets ASTM D 3420 (Part B).

Specimen sizes:
Square ““ 127 mm x 127 mm
Round ““ 127 mm diameter