Evaluation of Two Fully Rugged Laptop Computers for the Forest Service, Page11

Evaluation of Two Fully Rugged Laptop Computers for the Forest Service

Appendix D—Drop Tests

Purpose

This test evaluates the laptop's resistance to sudden shock or drop, ensuring that laptops can meet shock/drop requirements that reflect typical Forest Service field use.

Tests were conducted under the guidance of MIL-STD-810F, Method 516.5—Procedure IV (transit drop), nonoperating—modified to a 36-in drop onto 2 in of plywood. The test was modified to include six drops (one for each axis) rather than 26 as specified in MIL-STD-810F.

Equipment

Two 1-in-thick sheets of plywood were glued together to provide a surface for the drops. A 3-ft-long measuring stick indicated the drop height.

Two video cameras filmed the drops. One camera recorded an overall shot showing the complete drop. The other recorded a closeup of the drop area. A still camera was used to take photos of the laptops and any specific areas of interest.

PassMark BurnInTest software was used to test internal components of the laptops before and after the drop tests. The touch screen, touch pad, and keyboard were functionally tested before and after each drop test.

Procedure

PassMark BurnInTest software was run to test the laptop. The laptop was oriented to the proper test position and held by hand at the 3-ft mark. The video cameras were started and the laptop was dropped.

Still photos were taken of the laptop on the plywood. Additional photos were taken of anything that was particularly noteworthy. The laptop was inspected thoroughly.

BurnInTest software was run and touch screen, touch pad, and keyboard functionality tests were performed.

The procedure was repeated for each axis, a total of six drops.

Results

CF30: The CF-30 laptop passed all drop tests. On the first drop (bottom down), the cover to the hard drive port opened as did the fingerprint scanner cover. The hard drive cover may not have been fully latched properly before testing because it did not open on any subsequent drop tests. The fingerprint scanner cover opened on several of the other drop tests.
XR-1: The XR-1 laptop failed one of the drop tests. The case around the screen cracked when the laptop was dropped on the side with the CD/DVD drive (figure D–1). The laptop still passed all function and BurnInTest tests, although its structural integrity was compromised. It probably would not have been watertight.

Photo of the corner of a laptop where it cracked during a drop test.
Figure D–1—A crack developed on the XR-1 laptop after one of the drops.
The XR-1 laptop still functioned properly, but its integrity was compromised.
The CF-30 laptop passed all drop tests.

On most of the drops, many of the port covers opened (figure D–2). While this not a cause for concern for most of the components because they are sealed internally, the CD/DVD drive and PC card reader are not. If the laptop was dropped into a stream or lake, open covers would probably allow water to leak into these components and the laptop.

Two photos of a laptop. The photo on the left shows the covers of the drives and ports open and the photo on the left shows a laptop on the floor.
Figure D–2—The covers to drives and ports came open on most of the drops on
the XR-1 laptop. This could pose a problem if the laptop were dropped near water or
mud. One cover came open of the first drop on the CF-30 laptop. It is unsure if this
cover was fully latched before the drop. It did not open on any subsequent drops.

Conclusions

The CF-30 laptop passed all drop tests. One of the port covers came open on the first test. The XR-1 laptop failed a drop test when the case around the touch screen cracked. Additionally, many of the XR-1 laptop's port covers came open on most of the drops.