Newtek LVDT Sensors for Hazardous Locations 

Using contactless inductive technology, Newtek Sensor Solutions has introduced a new line of hermetically sealed position sensors that can operate safely in hazardous and explosive environments with the presence of flammable or ignitable gases and liquids. 

Approved for used in Class 1, Zone 0 and Zone 2 locations, the NT-HL-750 series of linear variable differential transformers (LVDT) are ideal for pipeline and LNG storage tank structuring monitoring and real-time position sensing of different valves in oil and gas fields, chemical process plants, gas turbines and oil refinery platforms and rigs.  

The AC-operated sensors can measure in a range from ±1.0 inch up to ±10.0 inches. They perform in a wide temperature range from 28ºC up to 150°C making them suitable for applications with fluctuating temperatures such as chemical process plants, oil refineries and power plants. 

An LVDT is a common type of position sensor that converts the linear position or motion of a measured object to a proportional electrical output that can be read by operators and control systems. Inductive transformers with frictionless operation, they have a near-infinite expected service life.  

There are two basic components: a fixed housing containing the single primary winding with two secondary windings and a movable core constructed of ferromagnetic material and mechanically linked to the measured object.  There is no physical contact between the housing and the core. The single primary coil is centered in the housing and energized with an AC signal.  Magnetically coupled by the core, a voltage is induced in each of two symmetrical secondary windings connected in a series-opposing circuit. The effective voltage and LVDT output is the difference between each secondary. When the core moves away from the center of the LVDT, known as the null point, the signal from the primary will be coupled to one secondary more than the other. See