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WISAN: Acquiring strain and acceleration in real
time 
WISAN platform
is being developed as a part of 
and 
projects, who's support we gratefully acknowledge.
Wireless Strain Sensor
The goal of the test was to test acquisition of simultaneous data streams from a strain sensor (BDI Strain Transducer) and an accelerometer.
The setup of the experiment is demonstrated in the next two figures. The strain transducer was attached to the bottom of a girder by two C-clamps. The box with electronics and the accelerometer was mounted on top and held in place by another two clamps. The strain sensor was connected to the differential signal conditioning input of the same box.
Full capabilities of the wireless sensor box include interfaces to a variety of single-ended and differential sensors as well as actuators. WISan-based wireless strain sensor and wireless acceleration sensors are described here.
Data from both sensor were sampled at 284Hz and 13bits of effective resolution and sent in real time to the base station connected to a notebook computer. Strain resolution established in laboratory experiments was better than 0.1 microstrain.
The following video shows real-time signals from the sensors (click image to play, Quicktime is required)
After data acquisition, girder displacement was computed from the acceleration signal in the frequency band > 2Hz. The following figure shows displacement vs. strain readings.
