When the temperature of food reaches the danger zone between 40 degrees Fahrenheit and 140 degrees Fahrenheit, bacteria like Staphylococcus aureus, Salmonella enteritidis, Escherichia coli, and Campylobacter can grow to dangerous levels and cause illness. At those temperatures, bacteria can double in number in as little as 20 minutes. For these reasons, food manufacturers, distributors, warehouses, and retailers must make sure that refrigerated and frozen foods stay cold until they are purchased or served.
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The cold chain refers to the succession of refrigeration steps along the supply chain used to keep perishable food in a healthy temperature range. The chain analogy is used to make clear that food quality is only as strong as its weakest link. If food temperatures fall out of range at any step along the way, that food can be compromised.
Food suppliers need to use proper refrigeration throughout the entire cold chain and implement a Hazard Analysis and Critical Control Points strategy to manage the cold chain and ensure food safety. Temperature monitoring, recording, and data logging technologies make that job a lot easier and provide an additional layer of protection.
Remote Temperature Monitoring Systems
Although commercial refrigerators and freezers come equipped with thermometers, many don’t have a way to alert users if the temperature strays out of the safe zone or if the power goes out. Having personnel check and record the temperature around the clock is impractical and unreliable. Just because the air and products inside of the unit feel cold, that doesn’t mean it is the appropriate temperature to maintain food safety.
A remote monitoring system can help companies in the food industry comply with FDA regulations, maintain accurate records, and, most importantly, keep food safe. These systems have alarms that send notification via phone call, text, or email to designated contacts when a temperature falls outside a preset range.
The base unit is the heart of the monitoring system. It pulls data (like temperature, humidity levels, etc.) from the sensors that are placed in key areas in a refrigerator or freezer. Users can select a base unit that communicates via a phone landline, Ethernet, or cellular connectivity. The system’s internal rechargeable battery backup ensures continuous monitoring and alerts in the event of a power outage.
When a monitoring system identifies a change in status outside of the preset range, it immediately sends alerts to people on the contact list. If users don’t want all of their personnel to receive notifications at the same time, some devices can be programmed to send alerts in a tiered fashion or on a schedule. Multiple communications methods like phone, email, and text provide extra assurance that the alert will be received.
It’s a good idea to check the number of people the system can reach and if the system automatically cycles through the contact list until someone responds. Some systems allow for flexible scheduling, so that off-duty personnel don’t receive alerts.
Programming and Status Check
For optimal performance, select a cloud-based system that delivers real-time status of all monitored conditions and sensor readings on demand. Options to access sensor readings include calling to check status, viewing a web page, or accessing it via an app on a mobile device. If a cloud-based system isn’t selected, users will be limited to logging in through a local area network. Both allow for programming changes, access status conditions, and review of data logs.
Temperature Probes and Buffers
There are different methods that measure temperature inside a refrigerator or freezer. The most basic instrument is the thermometer, which reads and displays temperature in the same simple device, while probes and sensors connect the environment or items being measured to more complex monitoring devices.