Developed by international shipper FedEx and tested with help from NIST, the Senseaware device connects to cell phone networks to provide users with near real-time information on a package’s precise location, temperature, humidity, pressure, acceleration, elevation and exposure to light. NIST researchers plan to deploy the technology as part of a pilot project to monitor and improve climate measurements. Credit: Strouse/NIST |
National
Institute of Standards and Technology (NIST) researchers are working to
reduce the uncertainty associated with climate-change measurements
using a mobile temperature-sensing technology made for tracking delicate
or perishable, high-value packages in transit. Developed by
international shipper FedEx and tested with help from NIST, the device
connects to cell phone networks to provide users with near real-time
information on the package’s precise location, temperature, humidity,
pressure, acceleration, elevation and exposure to light.
Historically,
package tracking has provided information to customers about a
package’s route and anticipated delivery date and time. Seeking to
provide customers with more information on the “vital signs” of their
shipments, the company approached NIST about the feasibility of
achieving accurate temperature measurements in a mobile device.
“The
primary function of the device is to monitor temperature-sensitive
materials such as medicines and vaccines, tissues, organs, blood, etc.,”
says Greg Strouse, leader of NIST’s Temperature and Humidity Group. “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.”
Once
all the kinks were ironed out, Strouse and his group worked with the
National Voluntary Laboratory Accreditation Program (NVLAP), a NIST
service that tests and accredits independent testing laboratories, to
help the company find a capable, independent lab to test the devices en
masse.
The
result was a palm-sized device that a customer can place inside a
package. The customer can monitor the transit of their package in real
time through a Web-based interface. A GPS receiver in the device
provides location information, and the device sends updates on its
status wherever it can get a cell phone signal. It even monitors the
shipments while aboard airplanes and transmits the data upon landing.
Accurate
to within 0.02 degrees Celsius and able to send and store data for up
to 30 days, the technology lent itself quite easily to another NIST
project focused on measurements for climate change. 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.
“Because
continuous measurement can be more informative than daily minimum and
maximum temperature observations, we’re looking into the potential for
using these devices as prototype weather stations and comparing their
results with the analog and digital style instruments used for weather
observations,” says Strouse. “Our goals are to better understand and
quantify the measurement uncertainty of both the historical analog and
current digital measurement systems as well as improving the science
base for metrology used in surface air temperature measurements.”
NIST
is planning to station three of the devices at locations around the
NIST campus in Gaithersburg, Md. The group intends to also erect a tower
to mount one of the devices to better understand 3-D temperature
gradient mapping strategies near the surface.
For more information on the new technology, see www.senseaware.com. For more information on NIST’s climate measuring activities, see www.nist.gov/climate-science-portal.cfm.