Abstract: A method for measuring the masses of objects in any gravity environment, including microgravity or zero gravity. An object is placed on or attached to a platform that is movable back and forth along a single axis of motion. An actuator is used to oscillate the platform and is controlled to provide a variable spring force. Instantaneous displacement values are obtained and used to calculate the period of oscillation. Values representing the period, the tare mass of the platform, and the spring constant are then used to calculate the mass of the object. The method may use active damping, and may be varied so that the oscillations are angular rather than linear.

Abstract: A device for detecting defects in the bore of a tubular member. The device includes an inspection head including an electromagnet for magnetizing the internal surface of a tubular member. The device also includes a sensor or sensors to detect magnetic flux leakage indicative of a defect. The magnetic flux sensor output is sent to a control-data acquisition system concurrently with signals as to the axial and circumferential position of the defect, which are obtained by their respective encoders. The control-data acquisition system is capable of processing and displaying the data in analog and digital form.

Abstract: A ferrous metal detecting apparatus is disclosed for detecting metal particles in a flowing fluid, such as engine oil. The detecting apparatus has soft-iron pole pieces with a bridging gap therebetween. The soft-iron pole pieces are electrically insulated from each other and magnetized by direct current through an electromagnetic coil. After a sufficient amount of ferrous metal has accumulated on the bridging gap, a level detector will give a warning signal and cause the electromagnetic coil to degauss the soft-iron pole pieces by applying an alternating current to the electromagnetic coil. After the flowing fluid has washed away the ferrous metal, the direct current will remagnetize the soft-iron pole pieces. If repeated warning signals are within predetermined time intervals, an indication of the amount of ferrous metal contained in the fluid can be interpolated. The recycling for repeated warning signals may be automatically provided through a timing circuit and control logic.