Data Loggers: There’s No Such Thing as TMI

Data loggers now seem nearly as pervasive in pharma plants as the data that they monitor and capture. In an environment where electronic sensor and measurement technologies have mushroomed, paper-dependent chart recorders are so last century. Plus, drug manufacturers are hyper-vigilant about process validation, so the need for instruments to capture and preserve data in perpetuity is great.

Pharmaceutical data logging has traditionally been the domain of devices that log and verify temperature readings as well as basic parameters like pressure and relative humidity during process operations. But depending on the process, key parameters such as pH, blend uniformity, liquid levels, equipment vibration, operator activity — you name it — may require constant monitoring and logging.

The modern plant is “well instrumented,” says Chris Felts, DeltaV system product manager for data integration products with Emerson Process Systems. Emerson’s solutions often act as the storage and operator interface points for much of the data measured by these instruments. Is there such a thing as TMI — too much information?

Not really, says Felts. “In the last couple of years, pharmaceutical manufacturers have been focusing on collecting all the data they can,” he says. “As data collection technologies advance and data storage capacities increase, customers believe it’s worth it to get as much information as they can.” In other words, better safe than sorry. “If you miss one important bit of information, you might end up having to throw a whole batch away,” says Felts.

FDA’s recent validation requirements, which leave it up to the manufacturer to determine which data is essential to prove control over their processes, have also been responsible for the current data logging boom, says Harper Howell, president of Ellab, whose products include temperature loggers for autoclaves, lyophilizers, and other harsh process environments. “There’s a fear in the industry that you have to over-document and over-test,” he says. It’s overkill, Howell admits, but he doesn’t see it diminishing any time soon.

Howell says that his company now has four times as many pharmaceutical customers as it did a few years ago, which has as much to do with technology improvements as with customer requirements. Wireless radio technology now makes it possible to, for example, monitor and log temperatures within a lyophilizer in real time. This is an improvement upon wired thermocouples and previous “wireless” logging technologies which could be placed anywhere but could only read after process completion. Real-time, wireless monitoring and capture is the “Holy Grail” for pharmaceutical data logging, Howell says.

Other data logging trends to watch include cheaper devices with more memory, lower power requirements, more rugged batteries and improved communication. Some units combine several functions — for example, sensing, converting sensed signals to digital form, and storing that digital data. Other units are just for storage, but often do so in prodigious amounts.

Loggers with flash memory cards such as those used in digital cameras to store and download data to PCs are increasingly popular — data is collected when the flash card is inserted into the logger. PC-based control and monitoring systems have assumed much of the workload once carried by distributed control systems. Mature data protocols such as OPC have enabled easier communication between sensors, loggers, PCs, data historians and other systems that manage and store critical manufacturing information. Ethernet- and USB-enabled data loggers have also proliferated.

Ellab’s TrackSense Pro Sky

These trends are carried over into facility-critical data capture and logging, too, says Felts: valve diagnostics, motor shaft vibration, current draw, and coolant temperatures. “Anything that will provide information on the health of capital assets will end up on loggers,” he says. “The big payoff is in reduction in downtime.”

With these thoughts in mind, what follows is a look at some of the most recent product offerings in data logging available to the pharmaceutical industry today.

Ellab released the TrackSense Pro Sky data logger, of which Howell speaks, in 2008 and will display the real-time, wireless system at March’s Interphex show in New York. The loggers can view real-time data in validation studies for lyophilizers, autoclaves, stability chambers, and freezers. Depending on the model, the devices cover a temperature range of -80° to 140° C and a transmission range of 50 feet.