A Web-Based Distributed Virtual Educational Laboratory

Evolution and cost of measurement equipment, continuous training, and distance learning make it difficult to provide a complete set of updated workbenches to every student. For a preliminary familiarization and experimentation with instrumentation and measurement procedures, the use of virtual equipment is often considered more than sufficient from the didactic point of view, while the hands-on approach with real instrumentation and measurement systems still remains necessary to complete and refine the student's practical expertise. Creation and distribution of workbenches in networked computer laboratories therefore becomes attractive and convenient. This paper describes specification and design of a geographically distributed system based on commercially standard components

A Client-Server Architecture for Distributed Measurement Systems

This paper describes a client-server architecture for the remote control of instrumentation over the Internet network. The proposed solution allows multiuser, multi-instrument sessions by means of a queueing and instrument locking capability. Client applications can be easily developed by using conventional high-level programming languages or well-assessed virtual instrumentation frameworks. Performance tests are reported; they show the low overhead due to network operation with respect to the direct control of instrumentatio

A Web-Based Distributed Virtual Educational Laboratory

Evolution and cost of measurement equipment, continuous training, and distance learning make it difficult to provide a complete set of updated workbenches to every student. For a preliminary familiarization and experimentation with instrumentation and measurement procedures, the use of virtual equipment is often considered more than sufficient from the didactic point of view, while the hands-on approach with real instrumentation and measurement systems still remains necessary to complete and refine the student's practical expertise. Creation and distribution of workbenches in networked computer laboratories therefore becomes attractive and convenient. This paper describes specification and design of a geographically distributed system based on commercially standard components

L\u2019incertezza di misura nelle valutazioni del campo elettromagnetico ambientale con l\u2019analizzatore di spettro in modalit\ue0\ua0 zero-span

Nelle valutazioni sperimentali del campo elettromagnetico ambientale, l\u2019incertezza di misura \ue8 un parametro che assume particolare importanza soprattutto quando i valori misurati approssimano i limiti di esposizione, o i valori di cautela, fissati dalle norme. Sono queste le situazioni che richiedono una maggiore accuratezza, al fine di individuare con particolare dettaglio i punti dello spazio che rispettano, o meno, i limiti fissati. L\u2019incertezza nelle misure con strumentazione a banda stretta dipende notevolmente da come l\u2019analizzatore di spettro \ue8 utilizzato. Nell\u2019utilizzazione tradizionale, basata sulla stima dei livelli massimi dei picchi visualizzati in uscita, \ue8 usuale ottenere incertezze elevate, dell\u2019ordine del 50 % o superiori. Diverso \ue8 il caso delle misurazioni in modalit\ue0 zero-span, dove il funzionamento dello strumento non risente delle problematiche riscontrate nell\u2019analisi tradizionale. Con questa metodologia di misura, l\u2019incertezza \ue8 un parametro che pu\uf2 essere ridotto in modo considerevole, agendo sia a livello di scelta opportuna di alcuni parametri di setup, sia prevedendo pi\uf9 acquisizioni nel tempo del segnale ricevuto. Quest\u2019ultima possibilit\ue0 richiede una corretta interpretazione del fenomeno in esame, che \ue8 possibile dare in modo completo ed efficace attraverso l\u2019interpretazione statistica dei segnali in gioco

Electric field strength evaluation of GSM base transceiver station with an analog spectrum analyzer in zero-span configuration

The paper presents a technique for the evaluation of EM field intensity produced by GSM-like base transceivers. The method is based on the use of an analog spectrum analyzer configured in zero-span mode and in a suitable processing of the analyzer results. A critical review of some spectrum analyzer characteristics will be also reported showing that in some cases large measurement errors are unavoidable, hence supporting the usefulness of the proposed method. Experimental results that prove the effectiveness of the technique are reported and discusse

A measurement system for the evaluation of environmental electromagnetic field

The paper presents a measurement system for the evaluation of electromagnetic (EM) field intensity in large geographical areas. It is based on the combined use of two test stations. The first one is equipped with global positioning system and broadband EM field sensors for preliminary data acquisition. The second test station is based on an analog spectrum analyzer for thorough investigation at locations where large intensity fields are found. The whole system provides geographical maps of the field strength. Control of the measurement subsystems through the Internet network for monitoring purposes is also achieved. Real life experimental data that show the system characteristics are discussed