| 摘要 |
A test object (21) and the master meter (20) are placed in an air channel to a fan unit, and are connected to an instrument (24) which compares the output signals from both of them, indicating any difference which may arise. Components (10, 11, 17, 18) are provided for fixing the object in the air channel which (11) is divided into at least three parts (5), and axialy displaceable units (15-18) permit coupling of the master meter and the test object between the channel parts. A manually adjustable damper is fitted in the air channel to regulate air flow. - The comparative instrument (24) is an electronic box with voltmeter, ohmmeter and so-called burn-off functions. This latter function is tested by pressing a button (27). The electronic box then simulates a fresh starting procedure, and if the burn-off function is fault-free, the filament in the test object glows for approx. 1 second, this being indicated by a light diode (28) illuminating on the electronic box. |
