A test sample is provided for testing performance of measuring and monitoring equipment for production lines, for example for foodstuffs or pharmaceuticals, and in particular, contamination monitoring equipment employing X-rays and/or metal detectors to spot foreign bodies in packaged products. The test sample may comprise a laminated card enclosing a standardised test piece such as a metal particle of specified size. The card or other sample bears at least one identification containing a barcode, readable by an optical scanner. To test the equipment, a card is placed on a product package passing through the equipment, the optical scanner reads the barcode to confirm that the correct test sample has been submitted, and the results for the test sample are recorded in a computer log. If the results do not match those expected from the particular test sample submitted, the equipment fails the test and requires recalibration or repair.