A black box (test dummy) is used for the daily routine check of the testing device; it is connected to the testing device. The system verifies whether the measured values determined by the testing device match those of the black box. If this is not the case, the testing device is locked. Use of the device is not authorized again until a black box test with a correct result has been performed. Since we only supply digitally evaluated test devices, we generally do not perform this test using a “pass/fail black box,” but instead use a single black box and evaluate the resulting measured values within tight tolerance limits.

If a black-box test results in an "N.O.K." (not okay) test result, the test device is locked. In this case, the cause of the measurement deviation must be identified and corrected. The test device is only released for use if the test result is "O.K." (okay).

The timing of the black-box test can be configured differently for each test device. This can be time-based or based on the number of units. As a rule, the black-box test is performed after the test device is turned on.

Each black box consists of a connection to the test equipment and one or more precision resistors and/or inductors. It can be designed for a single test method or for combinations of multiple test methods.

To ensure that the black box test steps are set up correctly, each black box is supplied with the resistance values and a calibration certificate.

The black box inspection complies with the harmonized European procedure for factory surveillance and inspection in accordance with CIG 021 and CIG 023.
CIG 021: Factory Inspection Procedures – CIG 021 specifies how inspections are conducted.
CIG 023: Factory Inspection Report – CIG 023 documents the findings of the inspection.