Conformance testing
Conformance testing or type testing is testing to determine whether a product or system or just a medium complies with the requirements of a specification, contract or regulation. This may apply to various technical terms as well as to pure formal terms with respect to obligations of the contractors.
Testing is often either logical testing or physical testing. The test procedures may involve other criteria from mathematical testing or chemical testing. Beyond simple conformance other requirements for efficiency, interoperability or compliance may apply.
To aid in the aim towards a conformance proof, various test procedures and test setups have been developed, either by the standard's maintainers or external auditing organizations, specifically for testing conformance to standards. Conformance testing is performed preferably by independent organizations, which may be the standards body itself, to give sound assurance of compliance.
Products tested conformance may then become advertised as being certified by the testing organization as complying with the referred technical standard. Service providers, equipment manufacturers, and equipment suppliers rely on such qualified data to ensure Quality of Service (QoS) through this conformance process.
Contents
Typical areas of application
Conformance testing is applied to various areas of application, as e.g.
- Biocompatibility proofing
- Datacom protocol engineering
- Document engineering
- Electronic and electrical engineering
- Medical procedure proofing
- Pharmaceutics compatibility
- Software engineering
In all such testing the subject of test is not just the formal conformance in aspects of e.g.
- completeness of filed proofs
- validity of referred certificates
- qualification of operating staff
but especially the aspects of e.g.
- operational conditions
- physical conditions
- applied test environments
Hence conformance testing leads to a vast set of documents and files that allow for re-iterating all performed tests.
Software engineering
In software testing, conformance testing verifies that a product performs according to its specified standards. Compilers, for instance, are extensively tested to determine whether they meet the recognized standard for that language.
Electronic and electrical engineering
In electronic engineering and electrical engineering, some countries and business environments (such as telecommunication companies) require that an electronic product meet certain requirements before they can be sold. Standards for telecommunication products written by standards organizations such as ANSI, the FCC, and IEC, etc., have certain criteria that a product must meet before compliance is recognized. In countries such as Japan, China, Korea, and some parts of Europe, products cannot be sold unless they are known to meet those requirements specified in the standards. Usually, manufacturers set their own requirements to ensure product quality, sometimes with levels much higher than what the governing bodies require. Compliance is realized after a product passes a series of tests without occurring some specified mode of failure. Failure levels are usually set depending on what environment the product will be sold in. For instance, test on a product for used in an industrial environment will not be as stringent as a product used in a residential area. A failure can include data corruption, loss of communication, and irregular behavior.
Compliance test for electronic devices include emissions tests, immunity tests, and safety tests. Emissions tests ensure that a product will not emit harmful electromagnetic interference in communication and power lines. Immunity tests ensure that a product is immune to common electrical signals and Electromagnetic interference (EMI) that will be found in its operating environment, such as electromagnetic radiation from a local radio station or interference from nearby products. Safety tests ensure 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.
For example, the telecommunications research and development company Telcordia Technologies publishes conformance standards for telecommunication equipment to pass the following tests:[1]
- 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 more antennas are used to measure the amplitude of the electromagnetic waves that a device emits. The amplitude must be under a set limit, with the limit depending on the device's classification.
- Conducted immunity
- Low frequency signals (usually 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, except 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 applied to the areas on the device that are likely 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 2 kV to 15 kV, but commonly go as high as 25 kV or more.
- Burst immunity
- Bursts of high voltage pulses are applied 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 applied to the line voltage.
Telecom and datacom protocols
In protocol testing, TTCN-3 has been used successfully to deploy a number of test systems, including protocol conformance testers for SIP, WiMAX, and DSRC.
Based on 3GPP and non-3GPP specification, the test equipment vendors develops the test cases and validated by the bodies.
