Apparatus Records Acceleration and Temperature

An apparatus records triaxial acceleration and temperature as a function of time, operating unattended for as long as 3 weeks on power supplied by two D cells. The apparatus, which has dimensions of only 3.5 by 4.5 by 2.2 in. (8.9 by 11.4 by 5.6 cm) and weighs only 28.5 oz (0.81 kg) is designed primarily to be attached to an article of commerce to log the shock, vibration, and temperature to which the article is exposed during shipment. The apparatus contains three digital accelerometers. It is easily programmed through a serial link to a desktop or notebook computer running Windows 95. When activated, the apparatus stores up to 8 MB of acceleration and temperature data in nonvolatile memory. The acceleration data can be stored as sampled (or, for efficient utilization of memory, can be preprocessed into such parameters as peak or root-mean-square acceleration or velocity) at a rate from 1 to 4,000 samples per second. The stored data are subsequently downloaded to a personal computer for display and analysis.