Beta-Ray Gage.--In the first installation of its kind, a General Electric beta-ray gage is being used at the Antioch, Calif., plant of the Fibreboard Products Corporation to help maintain accurate and uniform weight of milk carton paperboard.
The gage, mounted on one of the company's 136-in. paperboard machines, records the varying amounts of beta-rays absorbed by the board as it passes through the gage head of the non-contacting device. The amount of beta-rays absorbed varies with the weight of the board, thus allowing a constant check to be maintained. Variations as slight as one per cent from the desired weight per unit area of the board are automatically indicated and recorded.
Operators are able to make adjustments of the processing machinery as needed to produce paperboard of uniform weight. This is particularly important in the case of milk carton board and similar material that is run through folding machines which operate on extremely close tolerances.
According to E. H. Entricken, in charge of instruments at the Fibreboard plant, the G-E beta-ray gage is "more than a watchdog to prevent bad runs-it also aids in setting up new runs more quickly."
The gage, which is not affected by the speed, consistency, or temperature of the material being measured, may also be applied to plastics, rubber, metals, and special sheet materials where a continuous indication is desired. Since no part of the gage is in actual contact with the material being measured, it leaves no mark or scratch. Pre-service tests of helicopter blades and rotors are now being'conducted on actual equipment instead of scale models. Wright Air Development Center at Dayton does the job in two "whirley-bird cages" where all new and experimental rotors are tested for aerodynamic calibration for power and thrust, strain on various parts of the blades, and endurance. The larger cage is enclosed by six layers of chain link fence 75 ft. high and 100 ft. in diameter, uses a 4000 hp. electric motor to whirl rotors up to 90 ft. in diameter at speeds of 450 rpm. Floodlights permit night operation and overhead cranes lift rotors to the 50 ft. stand.