Prediction of system-level emissions performance via equipment shelf primary power bus frequency response characteristics
This paper reports an interesting extension of the frequency response testing technique to characterize real-world EMC conditions as encountered in the Product Realization cycle. It is demonstrated that the behavior of the Primary Power Bus of a system Equipment Shelf is a reliable predictor of the system’s EMC performance. In particular, the Conducted and Radiated Emissions characteristics of the system are anticipated before the system is fully assembled, and long before System-Level formal compliance testing is done. The frequency pass-bands and resonances of the Primary Power Bus are identified and these outcomes are closely correlated with independently obtained Conducted and Radiated Emissions spectra for the populated system Equipment Shelf.
Pre-compliance testing and characterization of equipment shelf EMC behavior by empirical frequency response measurements on the primary power bus
This paper demonstrates a frequency-swept measurement technique for predicting the conducted and radiated emissions performance of equipment shelves for pre-compliance and diagnostic purposes. The technique is based on the use of a vector network analyzer to identify the frequency passbands and resonances of the inherent coupling structure(s) presented by the primary DC power bus of the equipment shelf. The outcomes are compared with independently obtained conducted and radiated emissions spectra for the same equipment. Relevant data are presented and discussed. The technique is well suited for pre-compliance and diagnostic testing. It does not require fully populating nor powering the equipment shelf. The test is easy to perform and the information it provides goes a long way in optimizing or ranking alternate designs for electromagnetic compatibility.
Suitability and water quality criteria of an open drainage municipal sewage water at Coimbatore, used for irrigation.
Sanganur canal is the major open drainage system which has intricate linkage with storm water supply, domestic sewage and industrial effluent disposal. Water samples from various stations were collected and analysed for physicochemical parameters to assess the water quality of the Sanganur canal system. The study revealed that physicochemical parameters like pH, EC, TDS, DO, BOD, COD exceeded the permissible limit, clearly indicating the need of proper treatment of waste water before discharge into the Noyyal river.