I came across this interesting product for structural/geotechnical monitoring of cracks in 3 dimensions. Most crack monitors are designed for monitoring in 2 dimensions, this one can measure movement out of the plane of monitoring. I like that the markings are laser-etched so the simple device should last for a long time. Price is $40/each from Quality Plus Engineering, LLC.
,[Editor] From their video description: [/Editor]DeWind One-Pass Trenchers can install complete DEEP Groundwater Collection Trench Systems in a Single Pass Under the Groundwater Table! No Open Excavations-No Dewatering – No Pumping- No Treating discharge water- […]