NBS force calibration

The National Bureau of Standards has begun to use three new deadweight force‐calibration machines at its Engineering Mechanics Laboratory in Gaithersburg, Md. The machines have capacities of one million, 300 000, and 112 000 pounds. Loads can be applied in tension or compression with an uncertainty of 0.002 percent. Previously the load limit of the largest NBS deadweight machine was 111 000 pounds. The new machines have reduced the time required to calibrate one‐million‐pound force‐measuring devices by almost half and provide accuracies 10 to 50 times as great as were previously possible.