| 摘要 |
FIELD: physics; measurement. ^ SUBSTANCE: application: for pipe weld joint detection in ultrasonic control. Substance: consists that distance from active part of sensor to pipe surface rotated is measured with inductive transducer with analogue output perpendicular to pipe surface on rolled support. Obtained data are recorded with simultaneous registering of pipe rotation data using encoder. The moment weld joint reinforcing bead passes under active part of inductive transducer, reduction of distance from transducer to pipe surface is recoded. Detection of weld joint is recoded. To eliminate false operation, data processing algorithm is used, thereto repositioning of rotating pipe by 2 mm accompanies indication record of inductive transducer in buffer consisting of last 20 indications. All the indications recorded previously are backspaced to buffer end. The last "oldest" record is thus deleted, and new indications are recorded in buffer beginning. Then the first 10 records and the last 10 records of the buffer are summed. Obtained totals are compared, and if resulted difference exceeds preset threshold, controller programs generates event "weld joint detected". Operation threshold is chosen so that to provide reliable detection of welded joint and thus to eliminate false operations. ^ EFFECT: provided reliable pipe welded joint detection in ultrasonic control. ^ 2 cl, 3 dwg |
