Sensors/Data Acquisition

High-Shock Sensors

Diversified Technical Systems (Seal Beach, CA) has released the 6DX PRO, a high-shock sensor with six degrees of freedom. The three angular rate sensors (18000 or 50000 deg/sec) deliver position data, while the three accelerometers (2000 or 20000 g) are rated for high-impact environments. The 19 × 19 × 14.5-mm enclosure weighs 12 grams. The 6DX PRO is also sealed, IP67 rated, and compliant with NHTSA, FAA, ISO 6487, and SAE J211 practices.

Posted in: Products, Sensors

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Gas and Vapor Sensors on Paper

These sensors can be used wherever chemical or gas sensors are used, such as in mining, security, biomedical, food processing, and agriculture. Ames Research Center, Moffett Field, California Sensors on paper have been proposed and fabricated to identify gas or vapors (chemicals). Traditional sensors are based on hard substrates such as silicon. Sensors fabricated on paper are cheaper, foldable, flexible, and bio - degradable. Paper electronics is an emerging area. Logic devices, memory, RFID (radio-frequency identification) tags, etc. have been demonstrated. Sensors on paper will be another building block to achieve complete, true paper electronics.

Posted in: Briefs, Sensors

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Intelligent Flamefinder Detection and Alert System

This method detects and localizes both leaks and flames of hydrogen. Stennis Space Center, Mississippi While NASA facilities already use huge volumes of hydrogen as a propellant/fuel, many other federal and state programs across the country are looking at potentially expanding the use of hydrogen. There are, however, significant challenges associated with hydrogen use. These include a tendency to leak through seals (due to the very small size of the hydrogen atom) that ordinarily would efficiently stop most other materials, a very high diffusion rate, a huge explosive mixture range, and the fact that hydrogen burns with an invisible flame. Therefore, hydrogen leak detection is an important capability associated with a safe and operational work environment for NASA facilities, as well as at any other location/site that would potentially use this fuel. At the time of this reporting, there is not a technology that provides simple, inexpensive, and wide-coverage methods that enable large quantities of hydrogen to be monitored. Sensors that are available tend to be limited to either a very short range, or have no directionality. For instance, a standard hydrogen sensor detects an increase in hydrogen, but cannot determine if that increase is from a small leak nearby or a larger leak some distance upwind. A technology that is capable of alerting and providing emergency detection information about hydrogen leakage would be beneficial and increase overall safety.

Posted in: Briefs, Sensors

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Load-Indicating Sensor for Lines and Cords

Tension-indicating device will indicate the peak load that the cord is subjected to. Lyndon B. Johnson Space Center, Houston, Texas During the development of parachute systems, it is desirable to size the lines correctly, and to pack and deploy the parachute in a manner that produces uniform loading among the lines. Analytical methods would greatly reduce the cost of development; however, test verification is essential. This is extremely difficult to do with small lines, as there may be hundreds of lines in a multi-parachute deployment. The load-indicating sensors developed at JSC are extremely small, do not interfere with packing, do not change the load capacity of the lines, and can be inserted into an existing, assembled parachute system.

Posted in: Briefs, TSP, Sensors

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Wide-Input-Range Signal-Conditioning Input Interface for Motor Position Sensing in Extreme Environments

NASA’s Jet Propulsion Laboratory, Pasadena, California Motor position sensing is a critical application in a number of systems. Galvanically isolated sensors for motor position sensing are strongly favored in both industrial and extreme-environment applications. Two examples of these sensors are resolvers and linear variable differential transformers (LVDTs). Both of these utilize a transformer with a primary and two secondary windings whose coupling constants are variable with either shaft angle (for the resolver) or position (for the LVDT). These sensors are utilized by driving the primary winding with a sinusoidal signal and measuring the relative amplitudes of the secondary winding outputs. The resulting output waveforms have wide range (up to ±20 V for some applications), and are usually ground-referenced. It is thus critical to have a signal-conditioning interface circuit that can sense voltages across wide ranges and convert them to voltages that a standard integrated circuit can process.

Posted in: Briefs, TSP, Data Acquisition, Sensors

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Advanced Methodology for Precisely Simulating RTD Sensor Types

This technology has applications in plant process simulation, hardware-in-the loop testing of electronic control units in automobiles and avionics, and spacecraft and satellite systems testing. VTI Instruments Corporation, Irvine, California Resistance thermometers, also called resistance temperature detectors (RTDs), are very common sensors used for temperature measurement. Their reliability, ruggedness, wide range, and value make them popular in the process industry and research laboratories alike. A wide range of instruments, PLC I/O systems, data acquisition, and control systems are designed to interface with these sensors and perform actions based on their measured value. Testing of such systems requires a sensor to be simulated, where hardware-in-the-loop testing is mandatory. Often the validation of such systems will end up being a complex issue if not properly planned.

Posted in: Briefs, Sensors

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Microwave Radar Sensor Module

Applications include detection of humans from a distance for search and rescue, and non-contact detection of a patient’s vital signs. NASA’s Jet Propulsion Laboratory, Pasadena, California Existing implementations of continuous wave (CW) radar are not packaged appropriately for use as part of a heartbeat detection system for disaster search and rescue. They use separately packaged microwave components and laboratory test equipment, and require substantial skill to operate properly, including setup, calibration, and interpretation of the data.

Posted in: Briefs, TSP, Sensors

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