What is Conformance testing?

Posted on May 8 2009 - 3:30am by Raj

Conformance testing is a validation to ascertain whether a system meets some defined standard.

To assist in that, several test procedures and test setups have been built up, either by the standard’s maintainers or external constitutions, mainly for testing conformance to standards.

Conformance testing is frequently conducted by external organizations, sometimes the standards body itself, to give greater guarantees of compliance. Products validated in such a manner are then promoted as being certified from that outside organization as complying with the standard.

In software system testing, Compilers, for example, are extensively tested to determine whether they conform to the recognized standard for that language. It is a process of testing of an implemented product to conform that it is founded on its defined standards.

Electronic and Electrical Engineering

In electronic engineering and electrical engineering, a few countries and business organizations (such as telecommunication companies) ask that an electronic product conform to certain prerequisites before they can be distributed. Standards bodies such as ANSI, the FCC, and IEC, have definite standards that a product must meet before compliance is accepted. In nations such as Japan, China, Korea, and a few parts of Europe, products can’t be distributed unless they’re acknowledged to conform to those requirements specified in the standards. Commonly, manufacturers set their own requirements to ascertain product quality, some of the times with levels much higher than what the administrations require. Compliance is accomplished after a product passes a series of tests without occurring some conditioned mode of failure. Failure levels are commonly set depending on what environment the cartesian product will be sold in. For example, test on a product for used in an industrial environment won’t be as rigorous as a product applied in a community. A failure can include data corruptness, loss of communication, and irregular doings.

There are 3 important types of compliance test for electronic devices, emissions tests, immunity tests, and safety tests. Emissions tests ascertain that a product will not emit adverse interference by electromagnetic radiation and/or electrical signals in communication and power lines. Immunity tests assure that a product is immune to common electrical signals and Electromagnetic interference (EMI) that will be found in its operational environment, such as electromagnetic radiation from a local radio base or interference from nearby products. Safety tests ascertain that a product will not create a safety risk from situations such as a failed or shorted power supply, blocked cooling vent, and powerline voltage spikes and dips.

Common Tests 
Radiated Immunity
 
An antenna is used to subject the device to electromagnetic waves, covering a large frequency range (usually from 30 MHz to 2.9 GHz).
Radiated Emissions 
One or additional antennas are used to assess the amplitude of the electromagnetic waves that a device emits. The amplitude must be under a set limit, with the limit depending on the devices classification.
Conducted Immunity 
Low frequency signals (commonly 10 kHz to 80 MHz) are injected onto the data and power lines of a device. This test is used to simulate the coupling of low frequency signals onto the power and data lines, such as from a local AM radio station.
Conducted Emissions 
Similar to radiated emissions, but the signals are measured at the power lines with a filter device.
Electrostatic discharge (ESD) Immunity 
Electrostatic discharges with various properties (rise time, peak voltage, fall time, and half time) are employed to the areas on the device that are expected to be discharged too, such as the faces, near user accessible buttons, etc. Discharges are also applied to a vertical and horizontal ground plane to simulate an ESD event on a nearby surface. Voltages are usually from 2kV to 15kV, but commonly go as high as 25kV or more.
Burst Immunity 
Bursts of high-energy pulses are employed to the powerlines to simulate events such as repeating voltage spikes from a motor.
Powerline Dip Immunity 
The line voltage is slowly dropped down then brought back up.
Powerline Surge Immunity 
A surge is enforced to the line voltage.

Telecom and Datacom Protocols
In protocol validation, TTCN-3 has been used with success to implement a number of test systems, including protocol conformance testers for SIP, WiMAX, and DSRC.

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