Founded in 1974, Mountain Country Foods is a family-run business that evolved from a small beef-jerky manufacturer to one of the largest pet-treat manufacturers in the United States. As part of its overall quality strategy, the company has invested in experienced quality assurance (QA) staff, an in-house chemical laboratory and an effective hazard analysis critical control point (HACCP) program.
With such an emphasis on quality, access to accurate and timely process data is essential. To streamline and optimize the QA function, the company added a network of wireless environmental-monitoring sensors.
At the company’s Spanish Fork, Utah, processing facility, a series of four, 100-foot long ovens are used to bake the treats. Each oven has a number of zones that must be checked for proper temperatures. Until recently, checking and recording oven temperatures were manual and time-consuming processes.
“The ovens are the critical control point of our facility, and once product goes through, it is considered safe, sterile and ready to eat,” explains Caron McEwan, quality assurance manager for Country Mountain Foods. “As part of our HACCP plan, the temperatures need to be documented because they are part of our criteria for releasing the product. We had someone going every hour to look at the temperature of each oven zone on the digital display and write it down. Having to do all this manually took a lot of time.”
Additionally, with the manual process, there was no way to get a real-time view of temperatures during operation. Mountain County Foods knew that having such data would be helpful in understanding any issues that might be causing temperatures to fall out of range.
“We measure temperatures from 130 to 185°F [54 to 85°C], and unless you had someone standing there watching the oven all day, it was hard to know what was going on,” McEwan says.
Capturing Oven Baking Data
To overcome the limitations of manual temperature data collection, McEwan and her team researched new technologies and selected an automated datalogging and monitoring system. The system consists of 18 temperature/relative humidity sensors, a data receiver and software for managing the sensor network. The software allowed McEwan’s team to graph, analyze and export the temperature data. The system logs and wirelessly transmits near real-time temperature data from the network of sensors installed throughout the four ovens.
“We had previously used stand-alone Hobo temperature loggers for recordkeeping and saw that wireless versions had been introduced,” McEwan says. “We got in touch with an Onset application specialist to learn more and ended up going with the wireless system.”
The system overcomes one of the main problems of traditional wireless logging systems because each node does need not to be in direct communication with the data receiver. When powered with AC, each node can be set up in dual-purpose mode to act as a datalogging node as well as a router to pass on data from other nodes. Through the combination of routers and datalogging nodes, the system forms a self-healing network. This ensures that the data reaches the receiver via an alternate path in the event the existing path fails or is obstructed.
Although the receiver and the router are typically AC powered, they also have an internal battery backup so that temperature data can continue to be collected even during a power failure. Thus, the potential for collected data being lost is minimized due to the redundancy and backup built into the system.
Deploying the Datalogging Network
To create the sensor network, maintenance staff installed several of the hexagon-shaped wireless sensors in each oven zone. The sensors were mounted directly to the side of the ovens where the LCD readout and controls are. Cabled temperature probes run through conduit from each sensor into the oven.
The system’s data receiver is connected via USB to a dedicated computer running the datalogging software. The software displays a list of all data nodes and measurement points in the network along with near real-time graphs, displaying measurements as they are taken.
The computer is located in a centralized area so McEwan, supervisors and other Mountain Country Foods personnel can view temperature readings on screen as product travels through the ovens. The data also can be sent automatically at regular intervals to other computers through FTP and email or to a local network folder.
According to McEwan, installation of the system was straightforward and did not take much time.
Analyzing the Data
While the collected temperature data is primarily for documentation and recordkeeping purposes, McEwen looks at the data on a daily basis. To do this, she downloads the data in the datalogging software. Then, she uses the software’s export function to push the data to a Microsoft Excel file, where she reviews the daily temperature values.
“The wireless sensor system is still new to us, so we download the recorded data daily just to dot our i’s and cross our t’s,” she says. “We can then check the data against product-release records to make sure the product reached its critical point.”
In addition to the near real-time graphing and trend logging capabilities, McEwan and her team take advantage of the system’s alarm tools. They can notify the team of potential problems.
“I have our system set up so whenever a zone is out of target range, there’s an alert that comes up on the screen and I get an email and text message,” says McEwan. “This lets me know what’s going on at all times with the system at work and at home. I can choose to set targets above or below a specific threshold, or I can set a range. For example, if I want to set thresholds of 170 to 185°F (76 to 85°C) in a certain zone, the system will tell me if temperatures drop off or go too high.”
Since installing the wireless sensor system, Mountain Country Foods has been experiencing a number of benefits. First, the automatic data collection capabilities of the system have helped the company document oven temperatures for its HACCP program while doing away with manual checks. This, in turn, has freed up an employee to spend time working on other things. Second, plant staff now can view near real-time temperature readings during production, which enables them to keep a closer eye on the process and identify potential issues earlier. Finally, the system enables staff to be immediately notified by email and text if oven temperatures go outside of range, further helping to ensure product quality and giving McEwen and her team greater peace of mind.
McEwen is considering adding additional sensors to the network for even tighter control.
“We are currently looking at installing another heating oven in our facility and, with that, we’d want to track relative humidity levels along with temperature,” she says. “And, we have also talked about implementing wireless sensors in our freezers, particularly for the alarm capabilities, so we know if something goes wrong.”