Borehole Stressmeters (VW)

The Model 4300 Vibrating Wire Borehole Stressmeters are designed to measure stress changes in rock and can be installed in boreholes up to 100 feet deep. The Stressmeter consists of a high strength steel proving ring wedged tightly across one diameter inside a borehole and a vibrating wire tensioned across the other diameter inside the stressmeter. Changes in rock stress cause a related change in the resonant frequency of vibration of the tensioned wire providing output which is read by the Model GK-404 or Model GK-405 Vibrating Wire Readouts.