These strain-gauge type transducers electrically measure soil pressure and then convert this into mechanical strain, which is then detected with a strain gauge. These sensors have been widely used for testing and research as well as for installation and maintenance control on roads, bridges, tunnels, dams and other general structures.
There are two main categories of gauges. The KDE-PA/KDF-PA soil pressure gauges are each 50mm in outside diameter, and have a dual diaphragm structure. This makes them the quintessential product for conducting model experiments.
The KDG-PA/KDH-PA stainless-steel soil pressure gauges each have an outside diameter of 100mm, and are load-cell-type soil pressure gauges. They are designed to withstand a high level of lateral pressure, weighing in significantly heavier than the smaller type at 1.2kg (compared to 160g). The capacity of these gauges range from 200kPa to 2MPa, depending on the specific type.
These strain gauge-based soil pressure gauges are simple to operate and offer higher sensitivity and precision than either differential transformers or Carlson-type transducers. The rated output ranges from 0.3mV/V (600 X 10-6 strain) in the lower capacity models to 1 mV/V (2000 X 10-6 strain) in the larger models. Non-linearity is between 1-2% of the rated output, the load-cell type gauges being more precise.
All gauges in this range can be connected to all types of strainmeters, such as Data Loggers and dynamic strainmeters, for taking measurements. Hence multiple points can be measured automatically, providing convenience and simplicity.
These soil pressure gauges are available in Australia and New Zealand from Bestech Australia Pty Ltd.