Why Lab Refrigerator Temperature Alarms Are Crucial
What could go wrong? Perhaps the first thing that comes to mind is a power failure. If your facility does not have emergency generators that come online immediately, you need a backup plan to quickly move production to a backup refrigeration system.
Less likely, but not unknown, is a mechanical failure in the refrigeration system or a temperature excursion due to poor maintenance, such as icing on the evaporator coil. Another example is accidentally leaving the unit's door ajar. As a final example in this post, a temperature monitor that activates an alarm can fail.
For whatever reason, personnel must be alerted if the temperature is above or below the set value. Quick response to temperature excursions helps protect contents from spoilage or loss of potency.
Temperature alarm system
To understand the alarm system, we first set up the stage.
Temperature alarms are programmed by personnel based on the proper storage temperature of materials in freezers and refrigerators. Use a mechanical or digital thermostat to set the temperature.
Temperature monitors consist of probes placed in refrigerators and freezers and connected to onboard or external display and control devices. Many of these come with battery backup to maintain functionality in the event of a power failure.
For more information on temperature controls and monitors, see our post on the topic of vaccine storage.
On-board alarm
Examples of on-board systems include Nor-Lake Scientific laboratory freezers and refrigerators available from Tovatech. These feature digital LED microprocessor temperature controllers with high/low visual and audible temperature alarms and remote alarm contacts to alert personnel elsewhere in the facility. A temperature sensor is placed in the bottle filled with glycerin to better reflect the temperature of the contents than the ambient temperature in the unit. Such an arrangement also reduces the chance of triggering an alarm when the unit door is opened.
Some models of Scientific Refrigeration systems provide power failure alarms and door ajar alarms.
Auxiliary or optional alarm system
General purpose laboratory refrigerators and freezers can be equipped with an optional digital thermometer alarm consisting of an internal probe housed in a glycerin-filled bottle that is wired to external control and alarm devices.
Probably the best solution for notifying refrigeration failures is the iLab 600 temperature monitoring system from Tovatech. The device operates independently of the device by collecting data from an internal probe connected through an access port to an external pod, which in turn is connected to the facility's LAN.
The iLab 600 has two functions: A sophisticated programmable high/low temperature alarm that sounds locally and sends email, text, phone or pager alerts to the personnel list during off hours. It also captures, remotely stores and instantly retrieves compliance data reports on laboratory freezer and laboratory refrigerator performance.
An optional USB temperature data logger with built-in alarm can be used to automatically record internal temperature at user-programmable intervals using a NIST traceable probe. To read the results, simply plug the USB flash drive into the computer and transfer the data to the PC for viewing and archiving.
In addition to the onboard and optional digital thermometer alarms, an iLab 600 or USB data logger is recommended for two reasons.
First, you shouldn't rely on a single temperature sensor to drive a temperature warning system. There should be at least two completely separate monitoring systems with alarms linked to separate temperature sensors.
Second, they provide a way to acquire, store and retrieve stored temperature data based on good laboratory and good manufacturing processes.
Other Pharmaceutical Refrigerator Tips
Despite sophisticated temperature monitoring and alarm systems, laboratory personnel have a responsibility to protect the contents of refrigerators and freezers from spoilage due to improper storage temperatures.
Be prepared for prolonged power outages. Large facilities should have a backup emergency power system to keep refrigerators and freezers functioning properly. Smaller labs can use portable generators. If they shouldn't have procedures in place to quickly move valuable specimens, vaccines and medicines to off-site locations.
Keep in mind that full freezers and refrigerators will keep the temperature longer. Fill the empty space with an ice pack or water bottle.
Minimize unit visits. Temperature fluctuations occur every time the door is opened.
Publish operating procedures for monitoring and recording temperatures twice a day and instruct personnel to respond to power outages.
Contact
Thchamber Laboratory Freezer Manufacturer for details on protecting the contents of laboratory freezers and refrigerators from temperature excursions.