Key To Coming Of Age: Consistent Temperatures

Intermittent drops in temperature were, in fact, a problem. 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, there was a need for continuous temperature monitoring to pinpoint the cooler areas, and then take corrective action.

Heffernan first considered retrofitting the storage area with conventional temperature sensors. However, a more serious look at this approach suggested that installing hard-wired temperature sensors at many different 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.”

Heffernan ultimately selected HOBO® H8 dataloggers from Onset Computer Corporation. These are compact, battery-powered devices that are used for continuous monitoring of temperature, rh, light intensity, and other environmental conditions. These particular units also have external sensor inputs, which expand the range of measurement options and applications.

As standalone devices, HOBO dataloggers feature onboard processing and memory, can store up to tens of thousands of readings and can operate for up to one year on a single battery. According to Heffernan, 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,” said Heffernan. “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 HOBO Shuttle. The Shuttle is a pager-sized device that can offload and store the data from each logger, and then be taken back to a PC where the collected data can be graphed and analyzed using Onset’s BoxCar Pro software. “We were able to retrieve data from all the loggers in less than an hour.”

’Curtains’ For Uneven Temperatures

In looking at the results on the screen, Heffernan soon discovered that there was 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-in.-high capacity fans to circulate air across the lower region of the storage area. This, in effect, creates an “air curtain” that evens out the temperature to a steady 42?.

Since the HOBO dataloggers were installed in 2001, they have been running problem-free, and one datalogger has even survived a major fall. “Once, while I was riding around on one of the warehouse cranes connecting the shuttle to a logger, I dropped the logger from a height of 70 feet,” explained Heffernan. “We took the satellite down to ground level and tried to find the missing logger. I was able to find both halves of the outer case, but we couldn’t find the tiny circuit board ‘brain.’ After about 15 minutes of searching, we gave up. Five days later, during a routine inspection of the crane, we found the “brain” from the logger lodged in a recess on the crane. The logger didn’t miss a beat.”

Heffernan has since deployed additional HOBO dataloggers in the finished products area of the warehouse, and has also found use for them in monitoring current on the plant’s refrigeration compressors to ensure that they are running at the highest efficiency.