Simplified Linear Measuring System Uses Displacement Transducers

June 8, 2010 - PRLog -- Based on a four-arm Wheatstone-Bridge design with a nominal impedance of 350 Ohms, the design ensures excellent non-linearity, low power consumption and excellent temperature stability.  Additionally, the characteristics of strain gauge based sensors provide higher accuracy linear sensing than that of less accurate and lower resolution LVDT sensors.

Because these sensors operate at similar voltage levels and produce output signals compatible with other commonly used strain gauge sensors such as load cells and pressure transducers, they can easily form part of the same measurement chain in one central instrumentation system.  

These displacement sensors operate on low cost DC strain indicators or digital voltmeters, whereas standard LVDT transducers require conversion of the signals to achieve the same level of compatibility. The simplicity of this type of measurement requiring no further processing of the basic signal can make this test or measurement significantly more attractive to a user.

Additionally, strain gauge based displacement transducers exhibit typical non-linearity errors of a quarter of that of typical LVDT’s.  As with other strain gauge devices, the resolution is infinite and strain sensitivity is constant with a stabilized input voltage between 1.5Vdc and 15 Vdc.

These advantages are realised by Oxfordshire based company Fugro Offshore Geotechnics, who use these sensors within their accredited soil testing laboratories.  It is within these high-tech establishments where sub-sea soil samples are analysed and the sensors are used (together with submersible load cells, also from Applied Measurements) to monitor compression of the sample relative to the force applied.

As Fugro Senior Lab Manager Phil Robinson says, “we test soil samples from destinations all over the world and much time and considerable effort is spent retrieving them from sub-sea locations.  By the time we receive them, they are worth a great deal of money and cannot be replaced.  The tests can run for only a few hours or for several weeks and as we can only ever run a test once, we need confidence in our testing equipment and that the results can be relied upon.

The range of AML-SGD displacement sensors are precision assemblies contained within a rugged stainless steel outer casing. The internal construction of the AML-SGD transducer ensures a smooth, virtually frictionless movement of the inner core, resulting in high overall accuracy of

# # #

Applied Measurements offer a vast range of load cells, pressure, displacement and torque sensors and if a standard model isn't ideal, we can modify or reverse engineer to suit, or even produce a completely new design to suit your application.