Data Loggers Survive Airport Bomb Squad

When Massachusetts-based Onset Computer Corp., which manufacturers TidbiT® data loggers for tracking water temperatures, learned that Dr. Anne Jefferson’s underwater temperature loggers were water blasted by a Minneapolis-St. Paul airport bomb squad, they helped her recover the five months worth of data stored on them.

Jefferson, a research associate studying hydrology in Oregon State University’s Geosciences Department, was using the devices to collect water temperature data in stream channels along the Mississippi River. Over the Thanksgiving weekend in November 2006, she put the loggers in the trunk of a rental car she had been using over the holiday break. She and her husband forgot to look in the trunk when they returned the car to the airport. By the time they arrived in Oregon and found federal agents waiting for them at the gate, the damage was already done.

Minneapolis-St. Paul International Airport (Source: Metropolitan Airports Commission)

A rental car company employee was suspicious of the five, 1-foot lengths of PVC pipes filled with gravel that he found in the car’s trunk. Each contained three batter-powered underwater temperature-monitoring devices, called TidbiTs, which are slightly larger than bottle caps and have blinking LED lights.

The employee called airport police, who in turn called the FBI, who eventually brought in a bomb squad. When bomb-sniffing dogs found nothing, the squad removed the pipes from the trunk and used a high-pressure stream of water to “detonate” them. Nothing exploded, but the pipes were reduced to bits of plastic pipe and gravel.

After confirming her story with airport officials in Oregon, Jefferson said, “We drove two hours from the airport to Corvallis, and there was a message waiting from the Minneapolis airport saying that some of the loggers were still intact.” The message wasn’t specific, but did mention that some of the devices’ green lights were still blinking.

One of Onset's TidbiT underwater temperature recorders that withstood a blast by a Minneapolis-St. Paul bomb squad.

When Onset Computer caught wind of the story, according to its customer service manager Linda Cain, “We were able to contact Dr. Jefferson and let her know that we would like to try to retrieve the data from the loggers.”

Two long weeks after the incident, Jefferson finally received all the loggers in a sealed police evidence bag. Of the 15 battered devices, she was able to download data from most. She sent the remaining two loggers to Onset, where engineers were able to recover the rest of the data.

Having this temperature data is a tremendous relief. “The data was the study, the basis for my postdoctoral research,” said Jefferson, “and without it, there was going to be a problem.” It wasn’t only Jefferson’s research at stake; scientists from several other universities are also participating in the project.

According to Onset’s Cain, the data likely survived because of the nature of the loggers. The TidbiTs are designed to be submerged underwater and to withstand rough conditions. Data recorded by the device is stored electronically in EEPROM, which unlike RAM, retains data even when the power supply is cut off.

Overall, no great harm was done, though Jefferson hasn’t tried to fly anywhere or rent a car since the incident. “We’re probably on their blacklist,” she said.

Onset Computer Corp., of Bourne, MA, has produced small, battery-powered data loggers and embedded controllers since 1981. Contact: 800-564-4377 or www.onsetcomp.com