Macro Sensors’ LVDT Linear Position Sensors Provide Accurate Feedback of Valve Position in Nuclear Power Plants

Macro Sensors Radiation Resistant LVDT Linear Position Sensors provide accurate feedback of control valve position within nuclear power generation plants.

Constructed of stainless steel, the HSTAR 750 Series of Hermetically Sealed LVDT Linear Position Sensors  can be specified to withstand exposure to radiation at 3x10⁷ Rads for 40 years.

In nuclear power plants, radiation levels can be 100 Mega Rads.  As radiation values often exceed the limits of sensor internal electronics, the sensing element of Macro Sensors AC-operated, Radiation Resistant LVDTs are segregated from the electronic circuitry and operate with remotely-located electronics that power the sensor and amplify and demodulate its output. In the extreme conditions of nuclear power plants, the distance required between the sensor and electronics can range up to several hundred feet, limiting the use of inductive and magnetic technologies. As a result, LVDTs are more commonly used in power generation with extreme environments due to their robustness and high Mean Time Between Failures.

As a typical power plant contains a number of control valves, plant operators must always know their position. Plants have very precise control schemes for valve position to increase operating efficiency and save fuel.  Operating within the harsh environment of a nuclear power plant, Macro Sensors HSTAR 750 Series LVDT Linear Position Sensors provide highly accurate position feedback of valve position, supplying output to remote electronics or into a computer-based data acquisition system for statistical process control.

Available in ranges of ±0.050 inch (±1.25 mm) to ±10.0 inches (±250 mm), the LVDT sensors feature high resolution, excellent repeatability, and low hysteresis as well as the highest sensitivity consistent with good linearity. Electrical termination of the HSTAR 750 Series LVDTs is made through a sealed radial connector located near one end. The radial connector results in a through-bore design that permits access to either or both ends of the unit’s core for better mechanical support and core guidance, and easier cleanout in dusty or dirty locations.  The radial connector also has a shorter installed length, making the length of the Radiation Resistant LVDT Linear Position Sensors at least 2” shorter than comparable units with an axially mounted connector for easier installation in tight spaces.