Westbay Auditor collects the mechanical properties of your equipment enclosure, ranging from material properties to panel openings, along with the details of the emc (electromagnetic compatibility) specification and known interference sources. An Audit process then automatically assesses the possible emissions performance of the shielded enclosure compared with the specification, and produces an audit report.
The physical enclosure of an item of electronic equipment has a primary function of assembly and protection of the circuitry within, and also of protection of the user from dangerous voltages. The enclosure however can also play an important role in ensuring the equipment meets electromagnetic compatibility (emc) requirements.
The assessment of the emc capabilities of an enclosure unfortunately is not an exact science. It is more a combination of approximated theories and good design practice, and is frequently administered by an emc engineer. Emc is often poorly understood by electronic engineers, and poses an even greater challenge for mechanical design engineers, who may be involved in enclosure design.
Westbay Auditor provides an alternative approach, by providing a program to gather an enclosure's mechanical characteristics, to automatically apply emc theories on shielding, leakage from apertures etc, and to automatically apply qualitative assessments. The latter are based on sets of rules built into the program, but accessible and editable by the user.
A rigorous approach to review of the emc features of the equipment is enforced.
Westbay Auditor produces an isometric view of the enclosure, with a representation of features such as cooling vents, display openings, access panels etc. All enclosure views can be be displayed, using rotate left and right buttons, and flip up/flip down buttons.
A wide range of parameters can be set for the enclosure; the materials definition form is shown above, where the material properties itself are set, along with details of the surface finish. Shielding effectiveness is affected by material conductivity and permeability. Interfaces with panels are affected by surface finish properties.
The flow of operation of Westbay Auditor. After definition of mechanical features and emc requirements, the Audit Process reviews each feature against theoretical performance, and qualitative rules. Textual summaries are made of each of the fourteen audit stages, which can be viewed on-screen, and also written to a text file for importation into other applications.
The following features are supported by Westbay Auditor:
The internal noise sources definition form. A set of noise frequencies and field levels can be stored, and used in other projects. For example, a pcb which has been characterised can be used in conjunction with another enclosure project. Similarly, several noise files can be merged together into a new project.
The Audit Process makes use of several shielding analyses to calculate the basic shielding effectiveness, leakage from an aperture, cavity resonant frequencies, and attenuation due to a waveguide. These calculations are also made available directly to the user as a set of tools, allowing spot calculations at a particular frequency, and also shielding level versus frequency graphs. These can be saved subsequently as a .BMP file for use in other applications, or sent to the printer.
The Aperture Leakage form, which allows the user to estimate the
attenuation an opening in the enclosure offers to a radiated field.
The Audit Report can be written to a text file for import into other documents, or viewed stage by stage on the screen.
A powerful feature of the Auditor is the ability to create 'qualitative' commentaries. This allows the sort of comment an 'emc expert' might make to be inserted into the Audit file, by simply commenting that an aperture above a certain size for example, "is big enough to pose a potential problem". Standard conditions are provided, but the user can edit these, and create his own comments.
Westbay Auditor Lite can be downloaded free of charge.
Windows 95 or later. 2Mb RAM, 3.5Mb Hard Disk space.
Westbay Auditor is a trademark of Westbay Technology Ltd
Westbay Technology Ltd, Main Street, Baycliff, Ulverston, Cumbria LA12 9RN, England
Tel: 01229 869 798 (from the United Kingdom) Tel: +44 1229 869 798 (International) Contact by e-mail