NewTek Sensor Solutions

Hermetically-sealed, spring-loaded LVDTs by NewTek Sensor Solutions 

NewTek Sensor Solutions’ series of spring-loaded linear variable differential transformers (LVDTs) are designed to provide accurate dimensional feedback for a variety of position measurement and quality assurance applications.

LVDT position sensors for hazardous and explosive environments

The NT-HL-750 series of Intrinsically-Safe LVDT Position Sensors are approved for use in hazardous and explosive environments. These displacement sensors are designed to operate safely and accurately in hostile and corrosive environments where flammable or ignitable gases and liquids are present. The hazardous location position sensors are ideal for providing position feedback in pipeline monitoring, LNG storage tanks, oilfield equipment, petrochemical process control, gas turbines and power generation. The NT-HL-750 LVDTs are built with a stainless-steel construction and a welded ¾” hermetically-sealed housing, making them rugged and robust as well as shock and vibration tolerant.  Without on-board electronics that can fail due to hostile conditions, these AC-operated LVDTs offer long-term and accurate operation in hard- to-access hostile locations, common in HAZLOC applications. Sensors are approved by Intertek Testing Labs to carry the ETL hazardous location markings for use in Class 1 Zone 0 and Zone 2 areas. Intrinsically safe position sensors can only be used in Zone 0 locations. The NT-HL-750 LVDT Position Sensors offer a measurement range from +1.0 to +10 inches and perform over wide operating temperatures of -65°F to 275°F.  They are available with radially- or axially-mounted connectors. Electrical connections are made via lead wires exiting from a 1/2″ NPT fitting, making for an easy conduit installation.

Learning module for free-core and spring-loaded LVDT position sensors

NewTek Sensor Solutions offers a free downloadable learning module on Free-Core vs. Spring Loaded LVDT Position Sensors that focuses on the differences between the technologies and ideal applications. While both sensors convert the linear position or motion of a measured object into an electrical output that is displayed or input into a PLC, free core and spring-loaded LVDTs have different constructions. While free-core LVDT sensors have a floating core unit not attached to any coils, a spring-loaded configuration has a core connected to a spring-loaded probe shaft with a ball tip. Spring-loaded LVDTs also are available in air-actuated versions that operate with low pressure air that extends the sensor’s shaft. Probe contact force is regulated by air pressure so that when it is removed, an internal spring retracts the sensing probe to avoid any damage when gaging parts such as in an assembly line. While the free-core LVDTS offer high reliability with the absence of friction during operation as well as robustness for long life, spring-loaded LVDTs, also known as gaging probes, remain in constant contact with the measured object for highly repeatable and accurate measurement. They are popularly used in dimensional gaging of components as part of manufacturing quality assurance. The learning module discusses real-world applications for both technologies including the use of spring-loaded gage heads for measuring surface parameters on a manufacturing line and free-core LVDTs fo.

Hermetically-sealed 4-20mA sensors for process control and factory applications

NewTek Sensor Solutions offers its Hermetically-Sealed 4-20mA sensors accept long cables for process control and factory automation applications when standard lengths cannot reach distant control rooms, signal conditioners, PLCs and/or data loggers. The robust analog 4-20mA current loop output enables the use of longer cables from a sensor to a control system without electromagnetic interference or noise interrupting the signal and operation of associated equipment. The current does not degrade over long connections like voltage. Recalibration to correct for voltage drop due to cabling impedance is also unnecessary. As sensor cables transmit data and signals from a transducer to control units, they must be resistant to outside elements.

Intuitive LVDT Signal Conditioner

NewTek’s smart NTC-6000 Signal Conditioner takes out the complexity of setting up a signal processing system while protecting against operating failures and cybersecurity hacks. Both intuitive and user-friendly, the NTC-6000 Quik-Cal supports AC-operated LVDT, RVDT, or LVRT half-bridge sensors in converting unconditioned position feedback into a choice of voltage, current and digital outputs including 4-20mA, 0-5V, -0-10V and RS-485 formats. With intuitive programming, the Quik-Cal LVDT Signal Conditioner does not require technical personnel for configuration. Calibration is easy by using front panel indicators and pushbuttons to set zero and full-scale output positions. Following printed instructions and color-coded terminal blocks, general staff can complete the setup in just minutes. Units offer self-diagnostics that detect LVDT failures, disconnects, or short circuits. Cybersecurity lockout and tamper detection guards against third-party intrusions or data theft in unattended locations. Typically configured with sensors operating in harsh environments or extreme temperatures, the NTC-6000 signal conditioner is ideal for use in factory automation, materials testing, turbine control systems, steam valve positioning, packaging equipment, and dimensional gaging applications.

Linear position sensors for power plant applications

Hermetically-sealed linear position sensors from NewTek Sensor Solutions tolerate the high temperatures and vibrations of steam turbines to deliver accurate and reliable position feedback on the position of governor and throttle valves. Their high measurement accuracy also makes them ideal to monitor turbine shell expansion and bearing vibrations as part of process control systems. As power plants must operate to specific control algorithms, NewTek HAR-Series of AC-operated LVDTs can help operators determine when valves are closed or open and to what degree. Maintaining these algorithms ensure turbines operate efficiently and cost effectively. Providing feedback on turbine shell expansion, these sensors give operators the measurements needed to determine the thermal growth of steam turbines as the shell expands during startup, operation and shutdown. These measurements help identify if dimensions exceed expected temperature growth differentials. In addition, when installed on various locations on a steam turbine, the HAR-Series Hermetically-sealed Position Sensors monitor bearing vibration to detect bearing clearance limits that indicate bearing wear. HAR-Series LVDTs offer contactless measurement in a wide temperature range of -65°F to 275°F.

Position sensors with 400° temperature range

NewTek Sensor Solutions offers several LVDTs with an extended 400°F temperature range for use in applications where temperature spikes are possible. The high-temp, AC-operated position transducers ensure reliable position measurement without failure in applications with fluctuating temperatures where standard-temperature sensors can fail, due to deteriorating insulation and intermittent connections. For example, standard-temperature position sensors used on steam valves may unexpectedly fail when the valve is in motion due to temperature spikes caused by steam leaks. Failures also can result from hot gas outbursts or temporary exposure to opened furnace doors. Replacing these standard units with a higher temperature LVDT stops failures, eliminates bad readouts and reduces downtime associated with maintenance. Industries often specify high-temp LVDT position sensors for displacement measurement as insurance against units failing due to unexpected temperature spikes, which can be very common in industrial settings. The construction of a high-temp AC-LVDT also offers greater temperature flexibility in displacement measurement than other position sensing technologies such as potentiometers and magnetostrictive sensors.  Potentiometers rely on mechanical contact to provide position feedback, so components can wear and be affected by heat, making them noisier and less reliable over time.

Air extend/spring retract gage head sensors

NewTek GAR Series Spring-loaded Gage Heads are used in automated dimensional gaging applications as part of the inline inspection processes, when it is ideal for the sensor probe to move out of the way between readings. The probes of these LVDTs extends when taking dimensional measurements, and then retract to their original position to avoid damage to the sensor or next conveyed product. In manufacturing conveyor lines, these air extend/spring retract gage heads conduct tolerance checks as part of quality assurance measures. The LVDTs provide dimensional feedback to verify if parts have any variance in size and other physical properties.

Hazardous location position sensors ensure accurate valve position in chemical plants

Major chemical companies are using hazardous location position sensors from NewTek Sensor Solutions to monitor the state of different valves throughout their plants as part of process safety and efficiency management. Chemical plants using potentially explosive substances in their processes utilize different valves to control flow. Operators constantly monitor valve performance to determine if they are operating to specifications for optimal efficiencies.  NewTek HL-750 series of intrinsically safe position sensors monitor valve position in the harsh and hazardous environments of chemical plants, providing highly accurate displacement feedback to determine if valves are properly opened/closed, leaking or have failed. Certified for use in Class 1, Zone 0, Zone 1 and Zone 2 locations, the AC-operated position sensors operate safely and accurately in hazardous locations with flammable or ignitable liquids and gases.

Custom position sensor that detects part errors in automotive resistance welding machines

NewTek Sensor Solutions has designed a custom linear variable differential transformer (LVDT) position sensor for resistance spot welding machines used in automotive plants to detect missing or misaligned parts in nut and stud welding. Cars contain hundreds of welded nuts and studs that hold them together. Properly securing the right nut and stud to different car components is critical to safe operations. Working in conjunction with the resistance weld control equipment, the NewTek custom LVDT detects and reports different conditions including: weld pin extended position, double part, misloaded part, incomplete weld, weld pin retraction, upside down nut, wrong or missing part. Based on programmed system spec limits, the position sensor will trigger a go/no go response with each pass. Designed to fit inside the weld body of the machine, the AC-operated LVDT sensor has a very high stroke length ratio and excellent repeatability that is critical to the application.

AC-LVDTs serve as alternatives to magnetostrictive sensors

NewTek AC-operated LVDT position sensors often serve as a more reliable, precise and cost-effective alternative to magnetostrictive linear position sensors in the monitoring and control of valves in power generation and hydroelectrical stations. Because power generation environments can reach temperatures of 250°C (475°F), magnetostrictive technology might fail or become inaccurate over time. While very accurate in benign applications, most magnetostrictive sensors cannot operate over 85°C as electronics must be placed very close to the wand. With electronics separated from the LVDT coils, NewTek’s AC-operated linear position sensors continuously operate in power generation stations without failure at high temperatures. While the LVDT sensor remains in a harsher environment, NewTek’s NTC-6000 LVDT Signal Conditioner (which excites the AC-operated LVDT and provides a variety of output options for use in PLCS and other control systems) operates in a less innocuous environment.