Abstract: A phantom powered preamp for use with a microphone cartridge having a unique mechanical interface. The unique mechanical interface allows the phantom powered preamp to function with both ¼ and ½ inch microphone cartridges. The phantom powered preamp including a housing base having a PC board assembly and a connector, the PC board assembly being electrically coupled to the connector; a preamp tip having an adapter and a guard tube, the PC board assembly extending from the housing base to the preamp tip and being electrically coupled to the adapter and the guard tube, the adapter being configured to be electrically coupled to the microphone cartridge, the guard tube being configured to surround a portion of the PC board assembly within the preamp tip; and a first converter being configured to releasably engage the preamp tip or the housing base to reduce edge diffraction.

Abstract: A hand-held or portable vibration sensor device having a housing and a sensor body which generally provides a single point of contact with the machinery or apparatus for which vibration measurement is desired. In one aspect, the sensor body comprises a vibration sensor element such as an accelerometer for measuring vibration. In another aspect, a force sensor such as a force sensing resistor or load cell is provided to reduce the impact of forces applied to said hand-held vibration sensor such as a force applied through a handle during measurement. In another aspect, a compensation circuit processes the out put from a vibration sensor element to provide a relatively flat frequency response over a desired operational frequency range. The hand-held vibration sensor may also comprise a rubber isolation member disposed between the sensor body and force sensor.

Abstract: A mechanical vibration switch having a magnet connected to a bar that rotates about an axis, an inertial mass connected to the bar, a magnetic material part disposed in a predetermined spaced apart relation from the magnet, a spring, a stop, and an electrical relay mechanically actuated by the bar. The magnetic material part is adjusted parallel to the magnet such that the magnetic force varies approximately linearly with the common surface area S between the face of the magnet and the face of the magnetic material part.

Abstract: A hand-held or portable vibration sensor device having a housing and a sensor body which generally provides a single point of contact with the machinery or apparatus for which vibration measurement is desired. In one aspect, the sensor body comprises a vibration sensor element such as an accelerometer for measuring vibration. In another aspect, a force sensor such as a force sensing resistor or load cell is provided to reduce the impact of forces applied to said hand-held vibration sensor such as a force applied through a handle during measurement. In another aspect, a compensation circuit processes the out put from a vibration sensor element to provide a relatively flat frequency response over a desired operational frequency range. The hand-held vibration sensor may also comprise a rubber isolation member disposed between the sensor body and force sensor.

Abstract: A mechanical vibration switch having a magnet connected to a bar that rotates about an axis, an inertial mass connected to the bar, a magnetic material part disposed in a predetermined spaced apart relation from the magnet, a spring, a stop, and an electrical relay mechanically actuated by the bar. The magnetic material part is adjusted parallel to the magnet such that the magnetic force varies approximately linearly with the common surface area S between the face of the magnet and the face of the magnetic material part.

Abstract: An apparatus and system for sensing vibration in rotary or reciprocating machinery, such as motors, pumps, fans, gearboxes, compressors, turbo-machinery or high-speed spindles, which comprises a mechanical isolation member (14) interposed between a sensor base (15) and a main sensor body (11). In one aspect, the mechanical isolation member comprises a coaxial cylinder of plastic, rubber or polyurethane which is compressed between the sensor base and main sensor body.

Abstract: A transducer, including: a housing; a bridge sensor circuit disposed within the housing and including at least one micro electro-mechanical systems (MEMS) sensing elements and first and second output ports; circuitry disposed within the housing; and an input/output (I/O) line electrically connected to the circuitry, accessible at an exterior of the housing, and adapted for receipt of input voltage or current. The circuitry is for generating a single data signal that combines respective outputs of the first and second output ports, and transmitting the DC-coupled single data signal on the I/O line. The circuitry is for generating and transmitting to the bridge sensor circuit an excitation current or voltage using the input voltage or current.

Abstract: An apparatus and system for sensing vibration in rotary or reciprocating machinery, such as motors, pumps, fans, gearboxes, compressors, turbo-machinery or high-speed spindles, which comprises a mechanical isolation member (14) interposed between a sensor base (15) and a main sensor body (11). In one aspect, the mechanical isolation member comprises a coaxial cylinder of plastic, rubber or polyurethane which is compressed between the sensor base and main sensor body.

Abstract: A transducer, including: a housing; a bridge sensor circuit disposed within the housing and including at least one micro electro-mechanical systems (MEMS) sensing elements and first and second output ports; circuitry disposed within the housing; and an input/output (I/O) line electrically connected to the circuitry, accessible at an exterior of the housing, and adapted for receipt of input voltage or current. The circuitry is for generating a single data signal that combines respective outputs of the first and second output ports, and transmitting the DC-coupled single data signal on the I/O line. The circuitry is for generating and transmitting to the bridge sensor circuit an excitation current or voltage using the input voltage or current.

Abstract: A switch including a sealed housing; a magnetic sensor; and a control element configured to modify a control parameter for the switch in response to a signal from the sensor. In some aspects, the magnetic sensor is arranged to produce the signal in response to a magnetic field generated outside of the housing. In some aspects, the switch is a vibration switch, or is selected from the group consisting of a flow switch, a level switch, a temperature switch, a pressure switch, a proximity switch, and a velocity switch. In some aspects, the switch includes a two-wire configuration and first and second output pins arranged to provide an output signal for the switch and to receive a signal for programming the switch. In some aspects, the switch includes a two-wire configuration and a current-control element arranged to reduce current output for the switch.

Abstract: A switch including a sealed housing; a magnetic sensor; and a control element configured to modify a control parameter for the switch in response to a signal from the sensor. In some aspects, the magnetic sensor is arranged to produce the signal in response to a magnetic field generated outside of the housing. In some aspects, the switch is a vibration switch, or is selected from the group consisting of a flow switch, a level switch, a temperature switch, a pressure switch, a proximity switch, and a velocity switch. In some aspects, the switch includes a two-wire configuration and first and second output pins arranged to provide an output signal for the switch and to receive a signal for programming the switch. In some aspects, the switch includes a two-wire configuration and a current-control element arranged to reduce current output for the switch.

Abstract: A method and apparatus for sensing and measuring stress waves. The method comprises the steps of: a.) sensing motion, where the motion comprises a stress wave component and a vibration component; b.) separating the stress wave component from the vibration component with a high pass filter to create a signal proportional to the stress wave; c.) amplifying the signal to create an amplified signal; d.) processing the amplified signal with a sample and hold peak detector over a predetermined interval of time to determine peaks of the amplified signal over said predetermined period of time; e.) creating an output signal proportional to the determined peaks of the amplified signal; and, f.) repeating steps d.) and e.). The invention also includes an apparatus for implementing the method of the invention.

Abstract: A sensor connector assembly having a lower housing having a base operatively arranged to hold the sensor, and an integral male upper threaded section having a terminal block fixedly secured therein, an upper housing having a female lower threaded section operatively arranged to threadably engage the integral male upper threaded section of the lower housing, the upper housing also having an integral male upper threaded section having an aperture therein to pass a cable for the sensor, and, a sealing nut having a female threaded section operatively arranged to threadably engage the integral male upper threaded section of the upper housing and also having an aperture therein to pass the cable for the sensor.

Abstract: A sensor mount provides for attachment of a vibration sensor or other sensor to a machine without having to turn or rotate the sensor. In conjunction with a sensor module having an integral sensor and a shoulder formed at the outer periphery of the sensor module, the invention provides a coupler having a lower threaded portion for being threadingly engaged with a corresponding threaded recess formed in the machine. An externally threaded upper portion of the coupler remains exposed above the machine structure. A fastener is configured to attach the sensor module to the coupler by engaging the sensor module shoulder and the exposed upper portion of the coupler. The fastener may be captured to the sensor module or separable therefrom. When attached to a machine, the fastener and coupler are substantially symmetrically positioned with respect to a central axis of the sensor.

Abstract: A zero input current charge sensitive preamplifier comprised of a feedback means and, optionally, a charge cancellation means whereby the feedback means is comprised of a feedback loop having a feedback capacitor and a composite operational amplifier having a non-inverting input and being comprised of a common drain differential amplifier, having at least one junction field effect transistor which is coupled with a monolithic operational amplifier; and wherein the charge cancellation means is comprised of an integrator placed in the feedback loop at the non-inverting input of the composite operational amplifier.

Abstract: An instrumented test hammer for use in vibrationally exciting a test object includes a head assembly having an impact tip and a transducer operatively arranged to sense the force of an impact between the tip and object and to convert such sensed force into a proportional electrical signal, a handle extending away from the head assembly, and a cushioned grip surrounding a portion of the handle at a location spaced from the head assembly. The hammer is "tuned", by proper selection of the grip material and by selection of the ratio of the total mass of the head assembly to the combined mass of the handle and grip, such that the node of the first translational resonant mode of the hammer, after impacting against an object, is located substantially proximate the head assembly, independently of the manner by which the grip is held. The improved hammer substantially avoids the generation of spurious electrical signals due to post-impact vibration of the head assembly.

Abstract: A pressure generator for testing and calibrating pressure transducers has a body with an internal chamber. The chamber is filled with a liquid, statically pressurized. A piston is mounted in the chamber on a suspension member. A coil, mounted to move with the piston, is arranged in a magnetic field. The coil is supplied with varying current to cause the piston to oscillate or dither in the chamber. Such oscillation creates a dynamic pressure which is superimposed on the static pressure. Openings are provided in the body to receive the sensing end of one or more pressure transducers.

Abstract: A calibration arrangement in combination with ammunition testing apparatus comprising an elongated test barrel and a piezoelectric transducer mounted in the barrel and having a contoured end surface in operative contact with the outer wall surface of a cartridge to be tested. The transducer converts pressure changes into electrical signals which are translated through an amplifier to a voltmeter for readout. The calibration arrangement includes a pressure tube element adapted to fit in the test barrel with one end in pressure-tight relation with the interior of an empty cartridge casing held in the test barrel and with the other end of the tube adjacent the opposite end of the test barrel. The tube is held by a retaining assembly against lengthwise movement in the test barrel. A conduit connects a source of known hydraulic pressure to the tube for introducing known calibration pressure to the interior of the cartridge casing.

Abstract: A transducer for converting pressure changes into electrical signals wherein the pressure changes act on one surface of a relatively thin wall, such as pressure changes within a tube. A piston means on one end of a transducer housing and integral therewith has a contoured end surface conforming to the other surface of the wall opposite the surface on which pressure changes act. When the pressure changes are within a tube, for example within a cartridge casing in ammunition testing, the contoured end surface is concave. Piezoelectric crystal elements rigidly positioned within the transducer are deformed when pressure is applied through the wall to the contoured end surface of the piston means, and an output electrical signal is produced proportional to the applied pressure. Installation of the transducer in a test body is facilitated by a captive retaining nut rotatably connected on the transducer housing and having external threads for connecting in the test body.