Damage Dosimeter: A Portable Battery Powered Data Acquisition Computer

The Damage Dosimeter has been designed to fill a void in commercially available data recorders. The United States Air Force often has the need to measure structural strains and temperatures on in-service aircraft in order to diagnose difficult-to-analyze structural conditions, such as high cycle fatigue. To perform these functions a rugged, small, and lightweight data acquisition unit called the Damage Dosimeter has been constructed. Running off of battery power in an autonomous fashion the Damage Dosimeter measures 3 channels of strain at sample rates as high as 15 kilo-samples per second and a single channel of temperature. The Damage Dosimeter merges the functionality of both the analog signal conditioning and a digital single board computer on a single 3.5 inch by 5 inch card. The entire unit (sans battery) weighs less than 1.5 lb. and fits in the palm of your hand. This paper will discuss the motivation and requirements for the Damage Dosimeter, along with an overview of the design and construction. Finally, the software, operational modes, and sample data will be presented.