airstar-presentation forestry (3)
TRANSCRIPT
ULTRASONIC TESTING OF
FORESTRY PRODUCTS
JAN STRYCEK
AIR-COUPLED ULTRASOUND
Challenges and History
CHALLENGES OF AIR-COUPLED ULTRASONICS
REFLECTION LOSSES
♦ SPECIMEN : 60 - 90 dB
♦ TRANSDUCERS: 90 dB
♦ TOTAL REFLECTION LOSSES: 180 dB
METHODS FOR AIR-COUPLED ULTRASONICS
♦ High Ultrasonic Pressure
♦ Impedance Matching Layers
♦ High Voltage Transducers
♦ Toneburst/ Resonant Transducers
♦ Low Noise Pre-Amplifiers
♦ Digital Filters
♦ High Sensitivity
TRANSDUCER CONFIGURATIONS
TWO SIDED INSPECTION
longitudinalwave
shearwave
platewave
TRANSDUCER CONFIGURATIONS
ONE SIDED INSPECTION
pseudo pulse-echo plate wave
DEVELOPMENT AND HISTORY
Hp. Loertscher, B. Grandia, J. Strycek, W.G. Grandia:Airscan Transducers, Technique and Applications.
NDT net, Sept. 1996
J. Strycek, W.A. Grandia, Hp. Loertscher:Wave Modes Produced by Air-coupled Ultrasound.
NDT net, May 1997
J. Strycek, Hp. Loertscher:Ultrasonic Air-coupled Inspection of Advanced Material.
NDT net, Dec. 1999
J. Strycek, Hp. Loertscher, et.al:High Speed Large Area Scanning Using Air-coupled Ultrasound.
15th WCNDT 2000 Roma, NDT net 2000.
DEVELOPMENT AND HISTORY
Our First Instrument for Air-coupled Ultrasound 1986
AEROSPACE APPLICATIONS
ARIANE AND CHANDRA
AEROSPACE APPLICATIONS
F22 AND B-2
AEROSPACE APPLICATIONS
HIGH SPEED LARGE AREA SCANNER
AEROSPACE APPLICATIONS
HIGH SPEED LARGE AREA SCANNER
INDUSTRIAL APPLICATIONS
FOAM SCANNER
SOLID LUMBER
Eucalyptus and Radiata Pine
RADIATA PINE
Air-Coupled Ultrasonic C-scan
EUCALYPTUS
Air-Coupled Ultrasonic C-scan
SOLID LUMBER CRACK DETECTOR
2 CHANNEL LINEAR
SCANNER
SOLID LUMBER CRACK DETECTOR
High speed scanner
16 CHANNEL CRACK DETECTOR
SOLID EUCALYPTUS LUMBER
16 CHANNEL CRACK DETECTOR
TRANSDUCER AND INK
MARKING
BLOW DETECTORS
FRAME WITH TRANSDUCERS
BLOW DETECTOR
12 CHANNELS WITH THICKNESS GAUGES
BLOW DETECTOR
CABINET, PNEUMATICS, ELECTRICAL BOX
BLOW DETECTOR
TESTING LVL BILLETS
BLOW DETECTOR
LVL 3.5 INCH THICK
BLOW DETECTOR
LVL 16-CHANNEL
BLOW DETECTOR
LVL 16-CHANNEL
BLOW DETECTOR
PLYWOOD 32-CHANNEL
BLOW DETECTOR
PLYWOOD 32-CHANNEL
BLOW DETECTOR - FEATURES
♦ High Reproducibility
♦ High Signal to Noise Ratio
♦ Specifically adapted Noise Filters
♦ Works close to Ripsaws
♦ Works close to Press
♦ Suitable for very harsh environments
BLOW DETECTOR - FEATURES
♦ Low Maintenance
♦ User friendly interface
♦ Robust Ceramic Transducers
♦ Non contact Laser Encoders
♦ Remote maintenance
♦ Cluster defined Blows
♦ Auto-Calibration and Gain Control
BLOW DETECTOR - FEATURES
Standard and New Receiver Cards at min. Gain
LVL 3.5 inches
CLUSTERS
♦ TILE
♦ CLUSTER
Area for which the ultrasonic signal is tested and marked as accepted or rejected
Each channel represents one column of tiles, typically 1 inch long
Several rejected tiles can be defined to be connected in various ways
The size of a cluster is defined by the number of connected tiles
CLUSTERS
VARIOUS ENSEMBLES OF TILES
CLUSTERS
♦ INK MARKING
Clusters which include the minimal number of rejected and connected tiles are rejected
Rejected clusters are marked by ink on the test part and entered into the database
BLOW DETECTOR - INSTRUMENT
EACH CHANNEL: 1 PULSER + 1 RECEIVER
BLOW DETECTOR - CABINET
MONITOR, INSTRUMENT, PC,
ELECTRICAL PANEL
BLOW DETECTOR - CABINET
CABINET COOLER
BLOW DETECTOR - MONITOR
BILLET MAP, MARKED CLUSTERS, THICKNESS
BLOW DETECTOR - SOFTWARE
ADMINISTRATION
BLOW DETECTOR – CALIBRATION
TESTING CALIBRATION STANDARD
BLOW DETECTOR - CALIBRATION
CALIBRATION STANDARD
BLOW DETECTOR – CALIBRATION
CALIBRATION STANDARD IN PLACE
BLOW DETECTOR - CALIBRATION
ON CALIBRATION STANDARD
BLOW DETECTOR - PNEUMATICS
FOR AIR KNIVES
AND MARKING
BLOW DETECTOR – PERIPHERALS
TRANSDUCERS WITH AIR KNIFE
BLOW DETECTOR - PERIPHERALS
AIR KNIFE AND SHEAR PLATES
BLOW DETECTOR – PERIPHERALS
DYE SPRAYS AND THICKNESS GAGE
BLOW DETECTOR – PERIPHERALS
DYE SPRAYS AND THICKNESS GAGE
BLOW DETECTOR – PERIPHERALS
LASER THICKNESS GAUGES
BLOW DETECTOR – PERIPHERALS
LASER THICKNESS
GAUGES
BLOW DETECTOR – PERIPHERALS
LASER THICKNESS
GAUGESAND
AIR KNIVES
BLOW DETECTOR – PERIPHERALS
NON CONTACT LASER ENCODER
BLOW DETECTOR – PERIPHERALS
INFRARED TEMPERATURE SENSOR
BLOW DETECTOR – RESULTS
BLOW DETECTOR – RESULTS
BLOW DETECTOR
INVESTIGATING TRANSDUCER SPACING
R & D
PLYWOOD STANDARD FREQUENCY
R & D
PLY WOOD MEDIUM FREQUENCY
R & D
PLYWOOD HIGH FREQUENCY
INSTRUMENTS