Laser-scanned gauge gives on-line pipe measurements Extruded pipe, tube and hose can be monitored during production with a laser dimensioning system for use with plastics, rubber and glass, available from Industrial Monitoring Equipment. Inside diameter, outside diameter and wall thickness can each be measured by the Omega three-dimensional measurement and control system, consisting of a laser scanner for OD measurements, a nuclear backscatter gauge for wall measurements, and a controller that calculates ID.

A low power scanning laser beam is used to measure OD of manufactured parts or extruded profiles. The scanner consists of a scan assembly, a measurement zone and a receiver assembly. Resolution is of the order of 0.0051 mm and a minimum part OD is 6.35 mm.

Detection of 'backscattered' photons is the basis of the wall thickness gauge. The number of photons backscattered is proportional to the mass of the material and corresponds to the electrical pulses generated in the gauge. These pulses are amplified, shaped and stabilized before appearing as a direct measurement. Wall thicknesses up to 3.18 mm for non-ferrous materials can be measured (accuracy is :t: 0.0051 mm).

Closed-loop control is achieved with a microprocessor-controlled unit. This has an 'adaptive control' capability that automatically det- ermines and maintains the optimum settings of control parameters and simplifies operat- ing procedures.

Industrial Monitoring Equipment Ltd, Penn House, Penn Place, Rickmansworth, Herts WD3 1SN, UK

Ultrasonic system tests production-line axle shafts

An ultrasonic f law/integrity test system for production line testing of axle shafts has been introduced by American NDT. The computer- controlled AX-2200 system employs through-inspection along axle lengths of between 56 cm and 81 cm to detect chevrons or internal ruptures in the cold extruded part. Defective parts are marked and segregated at the discharge section of the machine.

Dual-gate mode of operation is employed as a fail-safe technique, ie if not enough ultrasonic energy

is transmitted to the back gate located at the flange end of the shaft, if the transducer were to die or the cable to sever, all shafts would be automatically rejected.

Frequency of operation is 1.6 MHz or 2.25 MHz depending on the size and length of the shaft. Power is supplied from a 450 V pulser, although the design is capable of variable power levels up to 1000 V.

American NDT Inc, PO Box 967, 671 E. Walnut Street, Lancaster, OH 43130, USA

American NDT's AX-2200 ultrasonic integrity test system for production line testing of axle shafts

Movement of the loom machinery appears to be slowed when viewed with the digital stroboscope type 4193 from Bruel and Kjaer

Stroboscope vibration test analyser Vibration test components can be observed using the digital stroboscope type 4913, a combined stroboscopic motion analyser and tachometer with built- in digital display from Bruel Et Kjaer. With its high-intensity hand- held flash source, stationary or slow moving images of any rapid repetitive motion can be obtained.

The stroboscope can be synchronized with motion frequencies up to 10 kHz and can be triggered from an internal generator or an external source. Separate modes with adjustable time and phase delay permit measurement at any required point in the motion cycle, and a 'slow motion' mode enables subjects to be viewed with an apparent motion frequency of 0.05 to 5 Hz. Motion frequency, speed, time and phase delay can be read directly from the four-digit display. Additionally, the choice of local or remote control, and single-flash operation for photographic purposes are offered.

Alongside the stroboscope, Bruel Kjaer have also released the stroboscope source Type 4915. This outputs point-source illumination through a 1.8 m long resilient fibre-optic cable for examining small mechanical components. The cable can be coupled with endoscope probes to examine difficult-access working mechanisms.

Bruel [~ I~aer (UK) Ltd, Cross Lances Road, Hounslow TW3 2A~ UK

NDT INTERNATIONAL . OCTOBER 1983 289