Macro Sensors annonce High-Pressure and Seawater Resistant LVDTs
To ensure the ongoing stability of offshore drilling platforms, the structural integrity of production risers, catenary risers, tendons, platform legs and braces are constantly monitored.
Macro Sensors (www.macrosensors.com) are specialists in the manufacture of LVDT-based linear position sensors with the capability to design high-pressure and seawater resistant LVDTs for incorporation into sub-sea measurement systems used to monitor the structural integrity of offshore platforms and pipelines.
LVDTs are designed for use in either pressure-balanced, oil-filled containers or directly in seawater. Some typical applications for LVDT-based sub-sea measurement systems include monitoring structural movement for a long-term FEA (Finite Element Analysis) of pipelines, derricks, moorings and other critical high stress members on offshore oil platforms.
When measurements must be obtained in seawater depths down to 7500 ft., with external pressure of approximately 3800psi and service life requirements are a minimum of 20 years, Macro Sensors designs its High-Pressure and Seawater Resistant LVDTs from 316SS and Inconel 625 for pressure and corrosion resistance. These materials enhance the already high-reliability of a LVDT assembly, ensuring it will continue to operate for minimum life requirements, even if the device is fully exposed to seawater.
Macro Sensors’ LVDTs also resolve the problem of getting a signal back to the surface, even in great water depths. To minimize the number of pressure-sealed connections and I/Os, a 4-20mA two-wire, loop-powered I/O can be utilized. A 4-20mA I/O also minimizes any noise over long transmission lines. Offsets can be easily made in the data acquisition system on the platform above. Another major advantage of using LVDTs for sub-sea applications is its extraordinary repeatability, regardless of offsets due to pressure and/or temperature.


