Still, the devices have a way to go before becoming widely used. "Low cost, portable data loggers with wireless connectivity are still relatively new to the market," says Knuth. "Once awareness of just how affordable they have become begins to grow, we'll see them commanding an ever-increasing share of the market."
Determining which type of device is right for your needs depends on several factors. "You need to determine the specs you need," says Young. "Consider factors like temperature range, number of data points, resolution, accuracy and cost."
Fettig agrees. "It depends on what you need to do," he says. "Processors, for example, are required to constantly measure and report on the continuous handling of their products. There must be a high level of integrity in the data to protect them and the consumer. Distributors, on the other hand, often only have to prove that their facilities maintain the proper environment and temperature. When they transport product, however, they are exposed and then they would turn to loggers to record in-transit temperatures."
Since cost is usually a factor, it's important to know that the price of these devices varies widely. "Commercial- and industrial-grade temperature sensors typically run $100 to $150," says Fettig. "Loggers range from $20 for a single use to $220 for multiple uses."
DiRubio says that when figuring out cost based on trailer load, you can expect mechanical devices to run about $10 to $20 per shipment, electrical devices to come in less than $30 per shipment, and wireless devices to range from $30 to $35 complete.
The important thing is that you find the right type of monitor for your needs, as Nestle did. Because in today's competitive market, runny ice cream just doesn't cut it.
Finding Hot Spots In The Cold Chain
Maintaining optimal temperatures throughout the cold chain is vital for perishable, refrigerated and frozen products. Whether in the warehouse, on the loading dock or in the trailer, failure to keep goods at the proper temperature can significantly shorten their shelf life or even render them dangerous.
Sensitech Inc., Beverly, MA, has developed a thermal-mapping system that allows distributors to monitor temperature in the warehouse as well as through transit. "Thermal mapping is a service that enables companies to find the hot spots and cold spots in either a facility or a trailer," says Jeff Leshuk, Sensitech's general manager of professional services. "The thermal maps are able to characterize the variation in temperature from location to location and over time."
According to Leshuk, the benefits of Sensitech sets up its TempTale electronic temperature monitors in a grid pattern throughout a facility or trailer to record temperatures. The monitors can capture up to 16,000 data points and measure temperatures in intervals of five minutes. In a facility, the monitors are in place for at least a week. "We prefer to get two weeks of data, however, because most facilities tend to operate on a weekly cycle, so we want to catch that variation over time," says Leshuk. "For example, you might not be operating a facility on a Sunday and all the doors might be closed so the temperature may be colder, and you'll have a different temperature profile at that time."
In a trailer, the monitors are in place during the duration of the entire trip and are recovered at the destination. Typically, an operator will map a sample of trailers'not the entire fleet.
The information collected by the monitors is downloaded into Sensitech's Cold Chain Manager reporting tool, which generates a map that provides three-dimensional views of temperature patterns. The thermal maps reveal temperature abnormalities, much like a weather map. "We show the gradients of temperature by color," says Leshuk. "The warmer spots are a reddish color and the colder spots are blue. Those colors will change over time and you can essentially run a video that shows the variation in temperature from location to location. It makes it very easy to identify hot or cold spots and then you can take action to correct those problem areas."