Making Cheddar Better
How Dataloggers Help the Aging Process
By Evan Lubofsky, Onset Computer Corp.
This story first appeared in the April 2003 issue of ThermoTech, a supplement to InTech magazine, the official magazine of ISAThe Instrumentation, Systems, and Automation Society. As a matter of policy, ISA does not endorse any commercial products referenced in their articles.
In natural cheese making, life begins at 40. At least that's the temperature at which the aging process can occur. However, if temperature conditions aren't just right, aging will not occur the right way. Tillamook, Ore.-based Tillamook Cheese, which makes naturally aged cheese and other dairy products, wanted to ensure that temperature conditions are optimal for successful aging in its automated warehouse. So along those lines, the company deployed more than 30 battery-powered dataloggers in various sections of the facility's block storage area.
"At Tillamook, we make natural cheese, not processed cheese," said Jim Heffernan, a maintenance technician at the Tillamook plant. "Part of the care and effort that goes into the process is making sure that storage temperature conditions remain at a consistent 42°F. If it's a little too warm, the aging happens too fast. If it's too cold, the aging doesn't happen at all."
The cheese maker was having a problem with intermittent drops in temperature. Airflow changes had been occurring, depending on how empty or full the storage area was, which in turn created areas that were too cold for proper aging. Thus, Tillamook needed continuous temperature monitoring to pinpoint the cooler areas and then take corrective action.
Heffernan first considered retrofitting the storage area with conventional temperature sensors. But a more serious look at this approach suggested installing hard-wired temperature sensors at many points in the area would be extremely time-consuming and expensive. "Since the warehouse wasn't initially set up for sensors, adding them after the fact would have taken months." Instead, Heffernan decided to go the datalogger route. The compact battery-powered devices continuously monitor temperature, relative humidity, light intensity, and other environmental conditions. These loggers also have external sensor inputs, which expand the range of measurement options, and applications. Heffernan said the loggers represented a quick and inexpensive fix to a critical climate control problem.
"The great thing about using battery-powered dataloggers was that we could deploy them immediately and start looking at temperature across all the various areas that we were concerned with," Heffernan said. "We got everything set up within a few hours, and the loggers started taking readings every six seconds." After a day of collecting data, Heffernan was able to retrieve the data using a pager-sized device that offloads and stores the data from each logger and is then taken back to a PC, where users collect the data and then graph and analyze it. "We were able to retrieve data from all the loggers in less than an hour."
After a quick scan of the data, Heffernan found a 4° temperature difference between the lower and upper regions of the storage area. To bridge this gap and create even temperature conditions, Heffernan installed two 20-inch high capacity fans to circulate air across the lower region of the storage area. This creates an "air curtain" that evens out the temperature to a steady 42°F
