PC-based test systems in harsh environment

PC based test systems are typically used in office and laboratory environments. Some systems can also be used in industrial environments where electrical noise, higher temperature, and dust prevent the use of the desktop PC. These test systems however will not survive the harsh environment found on the flight-line or otherwise outdoor use. Such harsh environment conditions include extreme ambient temperature, dust salt-fog humidity, EMI, rain, and the shock and vibration associated with portable or transportable systems. Until recently, test, data acquisition, and process control applications that had to meet such harsh environments had to be custom-designed. Some applications used a modified VXI chassis and some used custom electronics; these solutions were in most cases too costly and required an extensive development program prior to deployment. In other cases, the solutions were a result of numerous compromises that mitigated the original design goals to a point where the system became unusable. The question whether a PC-based system can be used at all in such environments has been asked numerous times with the answer being NO. However, following strict guidelines, a COTS (Commercial Off The Shelf) PC can be (and is being) used in the harshest environments. This paper discusses the problems associated with test equipment for harsh environments and demonstrates that the PC is a viable low-cost option for such applications.