Small data loggers take trips with perishable goods

Industrial Embedded Systems — January 14, 2008

Today, companies face more stringent commercial and hazard analysis standards than ever before. Whether centrally monitoring data from a fleet of trucks, large supermarket, or numerous workstations in a lab, businesses must deal with rigid restrictions and tightening profit margins. Furthermore, as the globe becomes smaller, with goods being imported and exported across vast distances, transportation procedures are becoming more complex and highly regulated. Protecting goods across long distances is becoming harder to accomplish.

Companies need simple devices that would give anyone, either driver or administrator, the ability to control the environment in which goods are kept. Temperature zone alteration should not be dependent on computer accessibility or limited by time, location, or software know-how. At the same time, protecting authorized software access is vital. Allowing anyone software authorization involves the risk of changing other set point parameters by mistake.

Logging the journey

Based on customer feedback, Fourier Systems developed a new mini-USB temperature logger. MicroLite (Figure 1) targets transportation applications and combines an easy-to-use USB interface, compact casing, and reliable data logging. It is particularly suited for the challenges of transportation in China and North America, where distances traveled during transportation are lengthy and perishable product loss can be costly.

Figure 1: MicroLite combines a USB interface, compact casing, and reliable data logging

This mini-USB logger is a small ìplug-and-recordî device for monitoring and recording temperature. Despite the compact design, data is clearly displayed on the loggerís numeric screen. The data logger has been dustproof and waterproof tested to meet IP68 standards. To further ensure global usage, the battery is easily replaceable since it is a standard model used worldwide.

The product is designed for ultimate application accessibility, whether mobile or static. Typical applications for this product include food, drug, and high-tech equipment transportation. Key to the success of this product in transportation is the loggerís high functionality and extremely low cost, meaning it can be discarded after use during a journey – a ìone-tripî logger.

Despite these benefits, data quality and reliability may be compromised because of the high 16-bit resolution (0.1 C), wide range of 40 C to 80 C, and high accuracy of 0.3 C. With a 16,000 sample memory and high sampling rate of 1 per second, data can be collected to the minutest detail over a long distance. The logger can stand alone during long journeys, thanks to the long-life battery and NanoWatt technology.

Analyzing the results

Stored data can be downloaded automatically from the data logger to the MicroLab Lite software (available for free at Software features were designed specifically in response to requests from the transportation industry among others, enabling a broader and more complex range of application environments.

The downloaded data can be displayed in graph or table form with alarm levels set. Data loggers also can be set up from the software with comments set for each logger. For the driver or administrator, material condition can be reported via daily status reports in various formats.

Basic analysis features include functionality, such as maximum, minimum, and average statistics, enabling a quick-glance summary of the environment and historical analysis. This is useful typically for applications requiring a constant birdís eye picture of the conditions in which materials are kept.

More advanced data analysis features include Mean Kinetic Temperature (MKT), an expression of cumulative thermal stress in different temperatures during storage, transportation, distribution, and pasteurization. MKT provides analysis for the most common methods of pasteurization: high temperature short time, ultra pasteurization, and ultra high temperature pasteurization.

Histogramming offers a graphical view of historical results presented according to defined parameters of time periods and percentage levels. This provides a level of analysis that can be tailored to specific environment needs for an immediate picture.

A feature of particular relevance to the transportation industry is Greenwich Mean Time (GMT) Recording, whereby data recording can be set to meet with GMT for use in international environments, particularly export and import.

The logger at work

A recent case study in which the Sea Star Seafood Corporation used data loggers to monitor highly perishable products during shipping indicates the value of data loggers in the transportation industry.

Established in 1983, Sea Star provides retail grocery customers case-ready frozen and refrigerated seafood products. Robert Soares, marketing administrator for Sea Star, describes how mini-USB loggers helped monitor these high-maintenance products during transportation.

ìData loggers ensure that the proper amount of frozen gel refrigerant packs is included in each shipment. Too few would result in product spoilage, and too many would result in excessive air freight charges. Data loggers provide accurate and reliable confirmation of temperatures during shipping, and result in substantial cost savings in air freight, refrigerant packs, and product loss.

ìDuring sample packing, a data logger is placed in the insulated shipping box with a postage-paid return envelope for its return to Sea Star after delivery (see Figure 2). The logger is programmed to start when the courier arrives to pick up the package. Samples are recorded at one-minute intervals during the overnight shipment. The logger is returned to Sea Star and the data is downloaded for analysis. Sea Starís requirements called for a water-resistant, compact, accurate, low-cost monitor, and MicroLite met all of these points. The intuitive, easy-to-use MicroLab software facilitates detailed analysis of the shipment from origin to destination and allows Sea Star to optimize its shipping process. This device has paid for itself many times over in shipping and materials savings.î

Figure 2: Data loggers placed in seafood shipments monitor temperatures at one-minute intervals during overnight shipment

Dov Bruker is the CEO and a member of the board of directors at New Albany, Indiana-based Fourier Systems, Ltd., which develops, manufactures, and markets advanced data acquisition systems for the educational and industrial markets. His experience includes work at APTEL, the Israel Air Industry, and Intelís design center in Haifa. He studied at Technion Israel Institute of Technology in Haifa, where he received a BS in Electronic Engineering.

Fourier Systems