NIST-Industry Collaboration Yields New Applications for Sensor Technology

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Innovative ideas can come in small packages, or, in this case, from a palm-sized package-tracking device. What began as testing by National Institute of Standards and Technology (NIST) researchers on a temperature-sensing device for packages that was developed by international shipper FedEx has generated research into several unexpected applications.

It all started when FedEx asked NIST to test the accuracy of temperature measurements made by its newly developed sensor device placed inside packages. The device, called SenseAware, was developed to monitor the environmental conditions of delicate or perishable high-value packages while in transit. It connects to cell phone networks to provide FedEx customers with near-real-time information on a package's precise location, temperature, humidity, pressure, acceleration, elevation and exposure to light.

NIST researchers conducted performance-based testing on the prototype sensor device and subsequent models as part of its Measurement Services. "The primary function of the device is to monitor temperature-sensitive materials such as medicines and vaccines, tissues, organs, and blood," said Greg Strouse, leader of NIST's Temperature and Humidity Group.

NIST's recommendations to FedEx improved the device, including one of particular significance. According to Strouse, "We tested the beta units when they were transmitting information and when they were simply recording it; and we found that the devices create heat when transmitting, which throws off the measurement. To fix that, we developed performance data and an algorithm that kicks in to correct the temperature measurement when the device is actively communicating." The devices are now accurate to within 0.02 degrees Celsius.

SenseAware is currently offered by FedEx as an added service that gives customers the "vital signs" of their shipments. It enables customers with sensitive materials, primarily from healthcare and science fields, to stay connected with their shipments through a Web-based interface. A GPS receiver in the device provides location information, and the device sends status updates whenever it obtains a cell phone signal. It even monitors the shipments while aboard airplanes and transmits the data upon landing.

As a result of his first-hand familiarity with the device, Strouse realized the potential for other applications, chiefly climate metrology. NIST is continuing the collaboration with FedEx and the manufacturer that now makes SenseAware for FedEx so the lab can use the technology for climate-change measurements. The goal of the research is to reduce the uncertainty associated with climate-change measurements.

The device's connectivity and accuracy make it ideal for monitoring surface air temperature, which climate scientists often use to evaluate the performance of their models and to better understand the meaning and uncertainty of historical surface temperature data. Currently, there are three devices stationed on the NIST campus in Gaithersburg, Maryland. The near-continuous measurements provide more information than the previous surface temperature measurements that occurred once per day. The sensors transmit data to the NIST researchers in batches every 15 minutes through a GPS system. Phase two of this research, set to begin in the spring of 2012, will enable NIST to build a more complex climate model by positioning the sensors at different heights. This will help to create a model of conditions such as heat islands or how winds work near the Earth's surface.

Strouse has identified several other applications for the device that may lead to future research projects. These include safety applications such as early warning of bridge collapses or forest fires. Yet another application seeks to identify potential structural issues related to the pouring of concrete for large-scale structures such as bridge footings and building foundations. An ASTM standard requires that test canisters of concrete be poured at the same time, with temperature monitoring for 30 days during the curing process. Use of the SenseAware device, with its continuous temperature monitoring capability, may provide more complete data about the curing process, which can be used to better predict structural safety problems.

This story of NIST-industry collaboration is one of many examples of how NIST researchers are able to recognize not only the emergence of innovative technology from their mission-oriented measurement-science research, but also to understand its implications for commercial application in multiple, often diverse fields. In particular, this effort continues NIST's long-time connection to the evolving needs of customers for NIST products and services in the private sector.