The d-GMM is a single channel Ground Movement Monitor that can be used to measure deformation or displacement in many different configurations. The instrument is designed to measure extension although since the shaft is flexible it can accommodate eccentric loading or shear. The d-GMM can be configured as a crack monitor or can be used for structural monitoring of shafts, headframes or barricades or as a closure station.
The d-GMM, is a magnetostrictive displacement sensor with a resolution of 0.01mm and a range of 145 - 290mm. The non-contact sensing technology is completely sealed against the environment and is fully temperature compensated. It has an on-board microcontroller running YieldPoint’s proprietary d-Tech signal processing and transmission technology to provide a high precision single point displacement sensor.
The microcontroller provides linearization, temperature compensation and outputs an ASCII encoded RS485 signal digital signal. Output signals can be transmitted over 250m/900ft without distortion. Each instrument is individually calibrated to ensure that the resolution (<0.01mm) and accuracy (0.25% typical) are an order of magnitude better than for similarly priced technology.
The digital form of the signals eliminates the necessity for expensive analog-to-digital conversion and results in low cost monitoring peripherals that output data in real world units (mm and degC). The instrumental is fully compatible with d-Logger, 1for1 radio and BluLink.