Abstract: The invention concerns a gas leak detector (1) having an inlet (3) enabling connection to a test piece or test chamber, a detector unit disposed within the detector (4), a high-vacuum pump (5) which is connected at one end to the detector unit and through which a test gas, such as helium, passes in the opposite direction, a back-up pump (6), a line (9, 13) joining an outlet of the high-vacuum pump (5) with an inlet of the back-up pump (6), and a line (7, 9) joining the test-piece connector (3) to the high vacuum pump outlet. In order to reduce the complexity and expense necessary to produce the back-up vacuum, the invention proposes that line (13) is fitted with a throttle (14) and including a further line (15) which is fitted with a valve (16), said line directly joining the test piece (3) to the inlet of the back-up pump (6).

Abstract: A monolithic substrate for acceleration and angular rate sensing. The substrate comprises a support frame, and a first accelerometer formed in the substrate. The first accelerometer has a proof mass including first and second opposite edges. A flexure connects the first edge of the proof mass to the support frame. The flexure defines a hinge axis for the proof mass. The first accelerometer further includes a torsion stabilizing strut coupling a portion of the proof mass to the frame.

Abstract: An exemplary apparatus for determining the thicknesses of individual layers in a multilayer article comprises an ultrasonic transducer coupled to the multilayer article with a buffer rod of similar acoustic properties, a pulser-receiver-amplifier which generates ultrasonic waves to produce discernible, time resolved pulse echoes, a digitizing oscilloscope which may be used to view the received pulse echoes, and a computer for controlling data acquisition and analysis.

Abstract: A system for authenticating bank notes by checking for raised print (37) produced by an intaglio printing process which only occurs on genuine bank notes. Each note (36) is individually transported past a pair of brushes (38) whose bristles are in contact with the two faces of the note. Microphones (28) are placed in close proximity to the brush means to sense the noise from the brush means which increases when there is raised print. Output from the microphones are digitized and applied to a data processing means (22) which determines whether the note contains raised printing, and hence whether the note is genuine or not, by generating a value based on the digitized outputs of the microphones (28) and comparing this value with stored values.

Abstract: Methods and apparatuses including programmed computers are provided for determining the initial concentration of diffusible particles in a sample stream introduced into a system wherein the sample stream which contains the diffusible particles flows in adjacent laminar flow with an indicator stream containing an indicator substance capable of exhibiting an observable change at a known concentration of the diffusible particles.

Abstract: A method and apparatus to gage the spacing between a plurality of handling elements used for transferring planar objects into and out of holding receptacles in a semiconductor process. The handling tweezers are moved to a checking location and fit interleaved with the gage apparatus. If the handling tweezers do not fit, the tweezers are moved to an accessible maintenance location for alignment and recalibration enabling its use for transferring semiconductor wafers to and from wafer holding receptacles in a chemical vapor deposition vertical diffusion furnace.

Abstract: A method is provided for measuring the agglomerative state of asphaltenes in a process flow stream of oil by applying an acoustic signal to the oil, detecting the scattered acoustic energy and using this detected signal to determine the relative particle size distribution of the asphaltene particles in the oil and/or their state of agglomeration. A method for controlling the agglomerative state of the asphaltenes which is based on the acoustic measurement technique is also provided.

Abstract: A gas sensor 1 has a catheter 3 to which a gas sensor body 4 and a signal guide member 5 for guiding a detection signal of the gas sensor body 4 are attached. The other end of the signal guide member 5 is connected to a connector 6. The gas sensor 1 is airtightly received in the reception body in the state where a connection terminal of the connector 6 is exposed to the outside. The reception body 2 is filled with a mixed gas containing a gas to be measured by a predetermined concentration. At the time of calibration, the connection terminal of the connector 6 is connected to a measurement amplifier while the reception body 2 is not opened and calibration is performed, and at the time of measurement, the reception body 2 is opened and the gas sensor 1 is taken out to perform ordinary measurement.

Abstract: An apparatus for repairing and/or leakage testing of sewer pipes, in particular of connecting pipes diverging therefrom. The apparatus is constructed as a tubular member and includes an opening, wherein the apparatus can be moved in the sewer pipe. The apparatus has a bladder which can be moved out through the opening.

Abstract: The invention provides a sensor arrangement for monitoring the concentrat of moisture and gaseous substances in ambient air. A gas sensitive intermediate layer is sandwiched between top and bottom electrodes, each of which comprises first and second interdigitated conductive elements, which are coupled to an opposite polarity voltage. The top and bottom electrodes are super-imposed on opposite sides of the gas-sensitive intermediate layer, with fingers of the top electrode having a voltage polarity which is opposite that of adjacent super-imposed fingers of the bottom electrode.

Abstract: A method and apparatus for determining the lubricity of an oil well drilling fluid, whereby a sample in a cell holder may be subjected to a desired pressure, temperature, kinetic friction, and lubricating fluid to simulate drilling conditions in a well bore, and particularly to simulate the drilling conditions of a non-vertical well bore such as encountered in horizontal drilling which generates sliding non-rotational frictional forces.

Abstract: A marker used for alerting people and animals of a span of line between attachment points has two identical parts for ease of manufacture and of assembly. Either gripper teeth are integral with the parts or partitions are integral with the parts and cooperate to grip the line to be marked.

Abstract: A method and apparatus for rapidly measuring nitrogenase activity of a nitrogen fixing plant growing in a medium in a non-porous container, is described. Gas containing hydrogen is sampled at the surface of the medium at a rate approximately equal to the rate of hydrogen diffusion from the medium, and the sample is passed to a hydrogen sensor where it is measured and nitrogenase activity is determined therefrom.

Abstract: Described is an apparatus and a method to accurately determine the gas entrainment characteristics of liquids, such as automatic transmission fluids. The apparatus comprises a liquid reservoir, a conduit having an inlet and an outlet connected to the liquid reservoir so as to form a pressurized recirculating loop for the liquid in the liquid reservoir, a pump for moving the liquid through the conduit, and a means for admitting gas (such as air) into the conduit to aerate the liquid.

Abstract: In order to obtain a reliable idea of the state of tightness for tightness testing of containers filled with liquids in which a pressure differential .DELTA.p is created between the interior of the container and its exterior, and also relative to the container wall in contact with the filling, an impedance measurement (7) is performed using measuring electrodes (3a, 3b) on the exterior of container (1).

Abstract: A method and system for determining the free cement content of concrete plant waste water held in a pit or tank P in which the temperature of the water in the pit or tank and the temperature of water in a reference pit or tank R.sub.1, is measured by thermocouples (T.sub.1, T.sub.2), the difference in temperature .DELTA.T determined and used to calculate an estimate of the free cement in the waste water whereby the reduced amount of cement to be used in a concrete batching process (without compromising the strength of the concrete product) can be determined.

Abstract: Typically, paint film thickness is measured at a plurality of locations on a vehicle body by a hand-held sensor which is positioned by an operator at a position normal to the respective locations being sensed. This operation may be inaccurate and time-consuming because substantial reliance is placed upon the operator. The invention provides an apparatus for positioning a plurality of sensors in contact with a plurality of locations, respectively, on a non-planar surface such that each sensor is positioned normal to the non-planar surface at the respective location on the surface. The apparatus includes a movable fixture and a plurality of pistons carried by the movable fixture. Each of the pistons is movable independently with respect to the fixture. Each piston includes a distal end, and a sensor is pivotally mounted to each distal end.

Abstract: A device comprised of at least a pair of accelerometers and a tilt sensor mounted in fixed relation to a datum defining plane (sole of a shoe) maybe used for extracting kinematic variables including linear and rotational acceleration, velocity and position. These variables may be resolved into a selected direction thereby permitting both relative and absolute kinematic quantities to be determined. The acceleration is determined using a small cluster of two mutually perpendicular accelerometers mounted on a shoe. Angular orientation of the foot may be determined by double integration of the foot's angular acceleration (which requires a third accelerometer substantially parallel to one of the two orthogonal accelerometers). The two orthogonal accelerations are then resolved into a net horizontal acceleration or other selected direction which may be integrated to find the foot velocity in the selected direction. The average of the foot velocity corresponds to the subject's gait speed.

Abstract: A bearing monitor for use with a canned motor pump having a wound stator and a rotor drivably coupled to an impeller, the rotor being mounted on radial journal bearings and axial thrust bearings within a containment can comprises a first and a second target embedded in an outer periphery of the rotor in axial proximity to a first and a second end of the rotor. The monitor includes a plurality of sensors mounted external to the containment can in axial proximity to each of the two targets and radially displaced approximately equally around the periphery of the containment can. A plurality of magnetic field generators create local magnetic fields coupled through the containment can, process fluid, rotor, and at least a portion of one target to one of the sensors. In response to each field, each sensor generates an output signal which varies as a result in a change in the magnetic circuit reluctance caused by bearing wear.

Abstract: A pipe layout system for secondary containment includes alternating deep and shallow penetration holes in containment boxes installed below gasoline dispensers, and a double-walled pipeline inclined downward from each shallow box to an adjacent deep box. Each deep box has a fitting which closes the end of the secondary piping within the containment box. These fittings have apertures positioned to face downward and communicating with a conduit which leads to a sensor mechanism at the low point of the conduit. If there is leaking gasoline within the secondary pipes, it will flow to the deep box, through the hole, and down to the sensor. A small amount of gasoline is all that is necessary to trip the sensor and shut down the primary product pipeline. In the shallow boxes, the same fitting is used to close the ends of the secondary piping, and the aperture therein is preferably positioned upward.