Sherborne Sensors LSOC: a market-leading Servo Inclinometer

A flexure suspension, high accuracy servo inclinometer, the LSOC from Sherborne Sensors delivers precision angular measurements and serves a wide variety of applications

Sherborne Sensors: The LSOC was developed in the 1980s. At that time, there were far fewer electronic instruments. Instead, mechanical inclinometers would be employed to accurately measure inclined surfaces. These were fine up to a point, and could offer a typical resolution of 30 arc seconds (approx. (0.008333°). However, a key drawback is that mechanical inclinometers require the user to be present in order to observe the output (much like using a compass or spirit level).

Moreover, mechanical precision level devices are bulky (typically being housed in a cast iron casing), the resolution is not as accurate as their modern-day electronic counterpart and, in applications such as weapons platforms – e.g. the gun turret of a tank – obtaining a measurement would be far too slow. With electrical terminations via 6-way bayonet lock connector (hence the acronym ‘LSOC’), electronic servo inclinometers mean the measurement can be obtained rapidly, and from any location, because it gives a voltage output that is much easier to monitor remotely.

Unrivalled performance in harsh environments

A further major difference between the LSOC and its mechanical predecessor is that it has a fluid filled servo mechanism area. Fluid damping employs a specialised viscous fluid that encapsulates the mechanical servo mechanism in order to provide both shock protection and to act as an additional filter attenuating unwanted background vibration. This ensures highly accurate output signals and makes the LSOC extremely robust. It is able to withstand mechanical shock of 1500g at 0.5 ms and still operate perfectly thereafter to provide highly accurate measurements.

The LSOC is suitable for a wide range of applications in typically harsh operating environments:

• Industrial – continuous casting monitors in the steel industry, which ensure guide tracking is within dimensional tolerances to achieve continuous quality production;  guidance systems for Tunnel Boring Machines (TBMs) that accurately monitor the position of the TBM when driving (digging) a tunnel.
• Mass transit – used in control systems to limit speeds of trains on corners for both safety and passenger comfort, with rugged construction ideally suited to long-term use; and for rail track monitoring to survey stretches of track and data record (resurveying and data comparison analysis highlighting track deterioration and the need for maintenance).
• Military – used on gun turrets for direct elevation control where severe levels of shock are encountered on recoil after firing; also used as part of sighting systems to give tank datum level in two axes.

Civil engineering applications

Other applications of the LSOC include geological surveys to monitor for subsidence in locations where there is movement of the land or a structure. This application is common in countries such as Japan, where construction companies will perform a geological survey before commencing construction of a planned development.

Similarly, LSOCs are employed to support civil engineering research projects. They are particularly important in the structural health monitoring of live structures. A designer might create a large structure such as bridge on their computer, and then use modelling software to simulate the effects of high winds, traffic and rolling stock going over the bridge, but validation of their design will be required – especially with health and safety now a primary concern.

Today, it is best practice to take between 200 and 300 inclinometers such as the LOC and position them at various points along a bridge to measure for very fine movements over time. The bridge would be monitored for several months and the measurement data recorded in order to identify the level of movement. At the same time, wind speeds and temperatures are recorded, in order to ensure that any movement of the bridge remains within the original design calculations.

Continuous improvement

Sherborne Sensors has continued to update the design and the electronics to enhance the performance of the LSOC. The unit may look similar to how it did in the ‘80s and it continues to perform in a similar way, but the specification has changed substantially over time and today’s LSOC delivers a far superior performance.

As such, LSOC remains the best and most cost effective type of servo inclinometer to offer for general purpose precision tilt measurements. Models are available in a variety of ranges from +/-1° to +/-90° with 4 to 20mA output. They are fully self-contained and able to connect to a DC power source and readout or control device, to form a complete tilt measurement system. They are environmentally sealed to IP65 and provide continuous operation in temperatures of -18°C to +70°C.

Sherborne Sensors has a long history of supplying the LSOC, and has manufactured more than 5,000 units to date since we began supplying them in 2002. Furthermore, many customers continue to return to Sherborne Sensors to have their LSOC units recalibrated for re-use.

Crucially, as a global leader in the design, development and manufacture of sensors for military, aerospace and industrial applications, Sherborne Sensors holds AS9100 Rev C certification, the internationally recognised quality management system for commercial aviation, space and defence organisations.
AS9100C continues to provide independent validation of our total commitment to delivering products and services of the highest possible quality and meeting our customers’ most demanding requirements for reliability.

While there are other manufactures of LSOC devices, none can match the heritage, expertise and market experience of Sherborne Sensors.
Find out more on what makes working with Sherborne Sensors special here: