Temperature monitoring is ideal for reducing bacteria and mold which otherwise may thrive and contaminate products and processes. Whether your cleanroom is designed around an assembly line, product compounding area, sensitive machinery, or another application, there are a few factors to consider before automating your setup including your regulatory needs, temperature range, sensor type, and sample rate.
Data loggers — or data recorders as they are sometimes called — record and store temperature and other values, encompassing a range of products including software and hardware. Whether you need a simple single-channel unit to log temperature or a multi-channel system to log several temperature inputs and other parameters at the same time, you can find a data logger to meet your exact needs. There are several common types of temperature sensors that are used with data loggers. You should go with the sensor type that’s best suited to your specific application.
Make sure you meet regulatory standards. U.S. cleanroom standards and regulations include the FDA’s CFR PART 210 and CFR PART 211 outlining cGMP relating to drugs and finished pharmaceuticals. ISO standard 14644-1 covers air cleanliness — effective temperature monitoring overlaps with this regulation as far as mold reduction etc.
Whether you want to go with an Ethernet or wireless setup is often already decided by your facility layout. However, you can make this decision depending on how you want to automatically transmit the temperature data. Ethernet-capable devices are often more affordable than wireless systems and can be mounted wherever you need to measure the temperature. The pod has connections for both external RTD and thermocouple sensors and can be plugged into an Ethernet port to automatically send your data to a secure server.
Even the most accurate system will only gather data where and when you tell it to. Again, your room layout will dictate some of these decisions depending on filter location, air flow, etc. Optimal placement areas include near HEPA filters, areas where personnel most commonly travel, and adjacent to any temperature-sensitive equipment or products.
Using data loggers for continual temperature monitoring and alarming enables cleanroom staff to stay in compliance by responding at a moment’s notice to out-of-specification conditions. Sophisticated alarms monitor the incoming data and can even send email, pager, or phone warnings to multiple recipients whenever an alarm is triggered. With automated alarming, you’re able to instantly contact staff so that equipment can be serviced or replaced without delay.
This Cleanroom Tip was taken from “Automating Cleanroom Temperature Monitoring” by Stew Thompson, which originally appeared in the May 2014 issue of Controlled Environments.