Data loggers track conditions during shipment. A second-generation, label-like unit with integrated temperature sensor and
USB connection point affixes easily to packaging (see Figure 1). The temperature sensor is calibrated during manufacturing to standards set by the US National Institute of Standards and
Technology (NIST) and is accurate to ±0.5 °C throughout its operating range of -30 to 60 °C. During transit, it takes a surface
reading of the object to which it is attached. Light-emitting diodes on the label flash if a temperature excursion occurs.
Once at its destination, an integrated USB connection point allows the label to be plugged directly into a computer, thereby
eliminating the need for a reader or proprietary software to download cold-chain data. The label automatically generates a
PDF file containing complete time and temperature history, including graphs and summary data. New features include an embedded,
comma-separated-values (CSV) file, which eliminates the need for third-party software to generate the CSV file. The embedded
CSV file lists time and temperature data in five-minute increments. The CSV file may be copied and saved to another location
per the user's standard operating procedures (SOPs). The data from the file may be manipulated using other programs in accordance
with company SOPs (BIOmed XpressPDF Temperature Monitoring Label, PakSense).
Figure 1: A label attaches to a package to monitor transit conditions (BIOmed XpressPDF Temperature Monitoring Label, PakSense).
The same compact form and USB technology is used for single-use data loggers introduced at INTERPHEX 2012. Units can be ordered
precalibrated and preprogrammed for specific temperature ranges (Cold Chain Logger CCL100, Vaisala).
Complete cold-chain protection also relies on sensors that monitor storage areas such as cold rooms, refrigerators, and freezers.
Battery-powered wireless temperature loggers provide alerts in real time if conditions deviate beyond set parameters. Some
models also monitor humidity or pressure as well as temperature. Sampling intervals can occur as frequently as once per second
with an accuracy of ±0.1 °C. The units also can monitor autoclaves, sterilization tunnels, and other temperature-controlled
areas. Proprietary software automates validation testing, ensures data security, and generates a variety of reports (XpertLog
Wireless Thermal Validation & Mapping System, Lives International Corp.).
A system based on radiofrequency identification (RFID) consists of an RFID smart card, capable of monitoring time and temperature,
an RFID reader with optional integrated barcode scanner, and the Internet (see Figure 2). The RFID smart card is placed on the pallet, individual case, or other designated location. To start the monitoring process,
the reader scans the pallet's barcode. Temperatures are recorded at specified intervals. When the shipment arrives at its
destination, tags are read to determine what temperature fluctuations have occurred. Results are transmitted via USB or Wi-Fi to a dedicated page on the Internet, and email and text alerts can be sent to supply chain partners. Smart cards
also may be returned by mail for download of the data, which is available online within 48 h. The tags can be restarted at
any time to record new segments. For example, as pallets are received, tags continue to record time and temperature in the
truck, on the dock, and in the warehouse. Tags can even be assigned new ownership and time and temperature parameters as the
shipment moves through the supply chain (TempTRIP web-based, cold-chain, time/temp monitoring process, TempTRIP).
Figure 2: Data gathered from package sensors is used to plot the cold-chain journey online, and red flags show when the load
experienced off-spec temperatures (TempTRIP web-based, cold-chain, time/temp monitoring process, TempTRIP).
Technology originating in Australia also makes use of active RFID technology, GPS, and Internet-based tracking software to
monitor products in-transit, warehouse, or refrigerator. The system, already in use in the food industry, collects data and
provides real-time alerts when temperatures deviate outside required parameters (Fresh InTransit, Fresh InSide, Fresh Mobile
hardware and software, CoolTrax USA).
New software allows access to data collected by a temperature-monitoring system or uploaded by supply-chain partners, such
as shippers, receivers, and carriers. The program instantly and automatically archives data on incoming perishable shipments
at the time of arrival. The wireless transmission to a secure server eliminates the need to download individual recorders
(Automatic Temperature Monitoring System, Cargo Data).
For receiving dock employees, a handheld device provides immediate access to temperature data, which eliminates the need to
wait for a download before deciding to accept or reject a shipment. The unit also transmits data for permanent storage (Express
handheld receiver, Cargo Data).