Multiprotocol control system monitors cleanroom air pressure, flow rates
BY JOHN WILLIAMSON
SCRANTON, Pa.— A high-speed micro- processor-based controller developed by Laboratory Control Systems (LCS; www.labcontrols.com) claims to provide a pressure and airflow control and response mechanism for contamination control in cleanrooms and other critical environments. When connected to a network, the Envirotrak IV system also supports record keeping for process validation.
Frank Crispin, president of Syracuse-based ASM Engineering LLC, has found that the Envirotrak IV system offers flexibility for airflow control and monitoring in pharmaceutical and similar applications. "We can isolate and independently monitor multiple air lock systems within a facility," he says. "The Envirotrak system is well suited for integration with variable speed fan systems, and provides immediate reaction and airflow modulation to maintain critical space pressurization."
In addition to pharmaceutical cleanroom applications, Envirotrak "supports semiconductor prototype development labs, BSL containment areas, and isolation spaces," says LCS President Steve Davis. "Along with pressures and flow rates, temperature and humidity are also monitored in any combination."
Envirotrak IV gathers airflow and other environmental data and sends it to a network that then provides a history of the environment for later validation. "At any moment in time, we have a record of air pressures and flow rates through a cleanroom," Crispin says. "We've specified the solution for ISO Class 5, 7, 8 and 9 (EU grades A, B, C and D) environments."
The unit can be positioned where needed, either near a terminal or remotely. The system is designed to integrate most building automation systems, such as ASHRAE's BACnet, Modbus, LonWorks and Johnson Control's N2. It also supports BACnet/IP communications through an optional Ethernet plug-in card that serves up Web pages to a standard Internet browser package, permitting remote monitoring of any automation system.
The system features a scan rate of 25 microseconds, a 1-MB flash memory and 1 MB of RAM. It incorporates up to 48 I/O control points and, according to the company, can be programmed to scan each individual point in any sequence desired without imposing limits on the application or number of downloadable graphic programs.
According to Crispin, "The system offers a single solution supporting contamination control in many types of buildings. We can field set parameters based on building design as well as change air monitoring requirements to conform with processing schedules."