Abstract: This invention embodies a method and apparatus for determination of surface resistivity (.rho.) of materials to be used for a desired purpose. The surface resistivity is obtained by measuring surface resistance (R) of at least one square area of the material, and converting the surface resistance into a surface resistivity (.rho.) by a correction factor K (K=.rho./R) whenever the total area of the material is greater than three square area. The surface resistance is measured by placing a pair of square electrodes, spaced from each other a distance equal to the side of the square, applying measuring voltage potential to the electrodes, and determining the surface resistance of said at least one square area. The surface resistivity of materials of any size can be obtained by multiplying the surface resistance value by a correction factor determined for the size of the material being investigated.

Abstract: A dynamic fuse testing device includes an elongated handle, a head pivotally mounted to the handle, a fastener for tightening the head relative to the handle to place the head and handle at a desired angular position relative to one another, a pair of elongated electrically conductive test probes for contacting opposite ends of a fuse, a pair of mounting members attached in spaced relation to one another on the head, the mounting members having respective outer ends mounting the respective probes, one of the mounting members being stationarily mounted on the head and the other of the mounting member being rotatably mounted on the head such that its outer end is pivotally movable toward and away from the outer end of the one mounting member for adjusting the distance between the probes to accommodate fuses of different sizes, and a lamp and battery on the head connected in series with the probes such that the lamp is illuminated by contact of the probes with a properly functioning fuse.

Abstract: A tool for grasping an electrical power conductor has a plurality of pointed pins mounted on a movable platform to pierce cable sheathing and insulation and contact a conductor of a cable held clamped in place by the tool. The pins are arranged so that at least one pin will contact the conductor to determine whether the conductor is energized.

Abstract: A hand held wand utilizes an elongated rigid hollow longitudinally extending stainless steel tube open at both ends. A data collection probe is disposed in one tube end. A data uploading port is disposed in the other tube end. The probe and port each include a stainless steel body electrically and mechanically engaging the tube. Each body has a front surface disposed outside of the tube with a peripheral annular ring and a central recess extending inwardly and terminating in a rear surface having a first opening. Each body also includes a corresponding longitudinally extending central electrode disposed in the corresponding recess. Each central electrode has an exposed front surface flush with the ring and a rear surface aligned with and spaced from the opening. Electrical insulation is disposed in the recess to electrically isolate the electrode from the body and the tube. The two bodies and the tube define a common external electrical ground with respect to the central electrodes.

Abstract: A self-contained, clip-on engine operating time log comprises a case containing circuitry for monitoring the accumulated operating time of a spark ignition engine. A plastic sensor, rigidly extending from the case, has two semi-cylindrical channels for clipping the time log directly onto an ignition wire of the engine. The sensor and the circuitry detect spark impulses in the ignition wire for determining the operating time of the engine. A liquid crystal display, visible through a window of the case, digitally displays the accumulated operating time.

Abstract: A spark plug voltage probe detects a voltage applied to a spark plug installed in an internal combustion engine so as to analyze a burning condition in the internal combustion engine on the basis of the voltage applied to the spark plug. A rubber collar (74) is provided to surround a rubber cap (7) which is secured to a high tension terminal (71a) of the spark plug (71) so as form a static capacity between the high tension terminal (71a) and the rubber collar (74). An electrical conductor (73) is provided between the rubber cap (7) and the rubber collar (74) and is electrically connected to a microcomputer by way of an output cable (64).

Abstract: A flat, modular measuring circuit having two connecting terminals for one phase of load current and a current sensor connected thereto. The two connecting terminals are arranged one above the other on one of the end faces of the module. This configuration leads to a significant reduction in the meter width and to a reduction in the production costs, since these modules can also be cost effectively produced in increased quantity and used for multi-phase meters.

Abstract: A power meter (10) is provided which can plug into an electric wall socket and it is provided with its own socket (16) for receiving the plug of an electrical appliance. The power meter has means for measuring electric current flow to an electrical appliance and indicates the amount of electrical power consumed by an appliance. In alternative embodiments, the meter is provided as an integral part of an electric wall switch (30) or wall socket (40) or it is built into an electrical appliance (50). In another embodiment, the power meter has a plurality of sockets for receiving the plugs of a number of electrical appliances for separately indicating the power consumption of each appliance.

Abstract: A signal probe apparatus having a probe tip, a grounding attachment, a main body portion and a connector for use with a signal measuring device. The probe tip and the grounding attachment are coupled by way of first and second signal lines to the connector for supplying signals therefrom to the signal measuring device. A plurality of circuit elements, such as resistors, are connected between the second signal line and a third line in the connector; and switch means located on the main body portion enables a predetermined circuit value, for example, the resistance between the second and third lines, to be selectively changed to a respective value which corresponds to a respective one of several predetermined functions which may be performed by the signal measuring device. The selected circuit value is detected by the signal measuring device and the corresponding function is thereafter implemented.

Abstract: The invention is a capacitively coupled probe which can be used for non-contact acquisition of both analog and digital signals. The probe includes a shielded probe tip, a probe body which is mechanically coupled to the probe tip, and an amplifier circuit disposed within the probe body. The amplifier circuit receives a capacitively sensed signal from the probe tip and produces an amplified signal in response thereto. The amplifier has a large bandwidth to accommodate high-frequency digital signals. Further, the amplifier has a very low input capacitance and a high input resistance to reduce signal attenuation and loading of the circuit being probed. The amplifier circuit is disposed in the probe body closely adjacent to the probe tip in order to reduce stray and distributed capacitances. A reconstruction circuit reconstructs digital signals from the amplified capacitively sensed signal.

Abstract: An electrical switch usable in an electrical test probe has electrical contact pads formed on a substrate acting as fixed electrical switch contacts. A frame member is laterally disposed from the fixed electrical switch contacts. An actuator is disposed within the frame member having a movable switch pole contact extending from the actuator past the frame member for wipingly engaging the fixed electrical contacts on the substrate as the actuator is moved between first and second switch positions. For use in a switchable passive voltage probe, the electrical switch is formed on a circuit board that is disposed in an electrically conductive tubular body. Insulating material surrounds the fixed switch contacts on the circuit board to electrically isolate the contacts from the tubular body. The switch pole contact reaches into the electrically isolated region to perform the switching function.

Abstract: A passive test probe apparatus 100 which provides high impedance and a relatively flat frequency response over a wide bandwidth. The probe apparatus 100 uses standard, non-lossy coaxial cable 130. The probe apparatus 100 employs a low capacitance probe tip 102 designed to minimize stray probe tip capacitance. The probe apparatus 100 uses a front-end (tip) resistor R.sub.t in series with a conventional RC tip network 240. The tip resistor R.sub.t provides two functions: First, it establishes a minimum input impedance for the probe input, and secondly, it provides approximately 80% of the high frequency attenuation when working into the cable characteristic impedance. In addition, a technique is described for determining an optimum length of coaxial cable 130 to be used in the probe apparatus 100. When the cable length is selected in accordance with the present invention, the crossover dip and other transmission line signal distortion effects are minimized.

Abstract: A regulator neutral detector comprises a pair of probes for engaging the source conductor and the load conductor, respectively, of an electrical utility voltage regulator and a digital voltmeter for indicating the difference between voltages applied to said probes.

Abstract: A measurement probe has a probe tip coaxially disposed within one end of a elongate cylindrical outer conductor with the probe tip extending beyond the end of the outer conductor. A body of insulating material surrounds the outer conductor and a portion of the probe tip to provide electrical isolation between the probe tip and the outer conductor. A notch is formed in the insulating material distant from the probe tip to expose the outer conductor for providing an electrical connection between an outer conductor of a removable adapter and the elongate cylindrical outer conductor of the measurement probe. The measurement probe meets all safety standards for use as a floating measurement probe as well as being adaptable for providing a coaxial signal path having a common voltage ground.

Abstract: A probe comprising at least one unshielded sensor tip and at least one transformer shielded within a conductive housing for sensing the electric field strength of a precise near field when connected to a radio frequency meter. Each enclosed transformer includes an annular ferrous core having a primary wire and a secondary wire wound thereon, with the input end of the primary wire extended slightly outside the distal end of the housing providing each sensor tip, and with the reference end of the primary wire connected to an annular conductor of a coaxial connector. The output end of the secondary wire is connected to an annular conductor of the coaxial connector. The reference end of the secondary wire and the shielded housing are connected to the annular conductor of the coaxial connector to provide a ground reference for the circuit.

Abstract: A cable assembly (A) is disclosed for a logic analyzer which comprises a flat woven cable (14) having an analyzer connector (18) and a probe connector (22). The analyzer connector includes a printed circuit board (32) and the probe connector includes a printed circuit board (34). Resistor-capacitor networks (D, E) are carried on respective PC board (32, 34) for extending the effective bandwidth of the cable assembly. A cable assembly (A") is disclosed having a low capacitance provided by high gauge signal conductors (92) and increased center-to-center spacing between the signal conductor and exclusively associated ground wires (94a, 94b). Resistor netowkrs (D', E') provide a high input resistance to the cable assembly. An interface shroud (B) connects terminal (C) of probe leads (10) to probe connector (22). A plurality of exterior grooves (54) are formed on an upper wall (44) of interface shroud (B) which receive locking arm (62) of terminal body (60).

Abstract: An apparatus is provided for inductive transfer of the scanning signal from a sensing head to a machine body. The apparatus includes cooperating inductive coupling elements between a receiving lug of the sensing head and the spindle of the machine. Cooperating coupling elements for inductive coupling are also provided between the spindle and the machine body. The coupling element of the receiving lug includes a coil with a ferromagnetic core. The spindle includes a second cooperating coil lying opposite to the receiving-lug coil which also includes a ferromagnetic core. The scanning signal is conducted from the detector to the coil in the receiving lug and is transferred inductively to the spindle. The scanning signal then passes over a transfer coil to a receiving coil. The transfer coil and receiving coil are configured such that the signal is transferred independently of rotation of the spindle relative to the machine body.

Abstract: A high voltage probe comprises a standard high frequency coaxial cable terminated in its characteristic impedance through most of the high frequency range, and a circuit of resistors and capacitors that provide a fixed division ratio regardless of the input frequency.

Abstract: Method and apparatus for identifying and determining the energization status of a cable having a conductive neutral member and an internal resistive screen layer involving probes radially movable relative to the cable to contact the neutral member and the internal resistive screen. Narrow-band AC signals and resistance measurements are utilized for self-testing and for cable testing. A microprocessor controls probe-heating in the advancing of probes through plastic sheath to reach the neutral wire and resistive screen layer. Resistance measurements made under control of the microprocessor are monitored with probe advance. Oscillators provide two signals of different frequencies, one of which is that of the power being transmitted through the cable, to provide distinctive signals indicative of cable energization status.

Abstract: A semiconductor device in which a plurality of circuit elements are disposed on a chip, and the respective circuit elements are connected to each other by a transmission line and an input/output probe pad for contacting a high frequency probe at opposite ends of the chip. The transmission line connecting respective circuit elements includes a separating section for connecting and disconnecting elements and an auxiliary probe pad that may be contacted by a high frequency probe disposed between the circuit elements.

Abstract: A measurement configuration which is particularly suitable for multi-probe measurement configurations and contains at least one linear measuring probe (10) which can be connected without any supplementary electronic circuit to standard measuring instruments, computers and printers or other evaluation devices (16). A display and control unit (70) can be attached to the linear measurement probe (10) in order to monitor the measuring process at the measurement location, or to transform the linear measuring probe (10) into a dial gage with analog or digital readout. A transducer and an electronic circuit are located in a cylinder (1) in addition to the guide bush for the measuring spindle. The electronic circuit converts the signals from the transducer into normalized measuring signals which can be directly processed by an external evaluation device (16). A cable (46) with a connector contains leads for signal transmission and a duct for controlling the measuring spindle for pressure variation.

Abstract: An improved electrical test probe has a electrically conductive strain relief adapter mounted on a substrate for accepting a conductive cable having a central conductor and an outer shielding conductor separated by a dielectric layer. The conductive cable is inserted into the strain relief adapter with the outer shielding conductor in electrical contact with the adapter. The substrate is disposed within an electrically conductive elongate hollow body with the body being deformed proximate the location of the strain relief adapter to secure the substrate in the body and to provide electrical continuity between the outer shielding conductor and the substrate and the outer shielding conductor and the hollow body. The adapter further provides strain relief for the center conductor of the conductive cable and mechanical support for the substrate.

Abstract: A hand-held probing device is adapted for use in testing the existence and amount of electrical potential in an automobile engine block or other object under investigation. The device has a specially formed housing from which extends a probe and a ground lead at opposite ends. The housing also includes a voltmeter and an electric bulb connected in parallel between the probe and ground lead. The housing also includes a switch which enables the device to be operated while held in one hand thus enabling the other of the user's hand to be free and usable for other functions.

Abstract: An electrical gauge structure capable of conveniently placing thereon one or two measuring bars is provided. The structure includes a housing, a fixing piece cooperating with the housing to define therebetween a clearance, and two retaining pieces provided on two sides of the fixing piece and limitedly slidably guided in the clearance so that when the retaining pieces are outwardly slid, they can position thereon the measuring bars.

Abstract: It has been found that the ground lead of a measurement instrument probe has an inductance which, when coupled with the capacitance of the rest of the probe, forms a resonant circuit. The net result is a peak in the frequency response of the probe which interferes with accurate amplitude measurements of test signals having a frequency above some threshold. Pursuant to the present invention, a resistor is added to the measurement instrument probe whose value substantially flattens the frequency response of the probe and permits accurate amplitude measurements over a substantially greater frequency range. This resistor, either having a fixed or adjustable value, can be added to the measurement instrument probe or can be included in an adjunct which fits over a probe end.

Abstract: A hand held sensor body with a manually extendible two-pronged probe contains an ion meter for both chlorine concentration and for pool water acidity. The sensor is D. C. powered and the probe has dual metallic rods extending from the hand-held probe and terminating in alloy sensor tips. The body of the sensor containing the meter also detachably encases the hand-held probe when the probe is not in use. The meter case tapers downwardly in width to a battery chamber with access for the probe cable. The battery chamber has contacts for connection to the meter and an electrical contact for the control knob for an adjustable potentiometer imposed in the electrical circuit between the meter and the probe.

Abstract: A monitor for detecting miswiring in standard 3-spade AC electrical outlets. The monitor includes a housing, prongs for insertion into the outlet to be tested, outlet ports for an external plug, and a banana jack for a wrist strap or other anti-static device. If the outlet is properly wired, a lamp will illuminate. If, however, the outlet is miswired, one of two silicon controlled rectifiers will shunt current around the lamp, extinguishing it, indicating to the user the presence of a faulty outlet. A junction field effect transistor is also provided to activate one of the silicon controlled rectifiers when one particular miswiring condition is present.

Abstract: A portable bar-to-bar armature tester for testing motor armatures for adequacy of their coil windings is disclosed. The tester is to be held by hand, such that four electrical probes, which extend out of the forward end of the tester, contact with four adjacent commutator bars of the armature to be tested. The tester includes a voltmeter in circuit with two of the four probes, and a toggle switch, a rheostat and a D.C. source in circuit with the two other of the four probes. The circuitry is all housed in a hard plastic casing to protect the circuitry from electrical contact with other objects and to protect the circuitry from damage due to dropping or dirt accumulation. The four electrical probes are laterally adjustable and are contacted with four adjacent commutator bars to determine whether the coil windings, are unbroken and properly wound.

Abstract: For use with a circuit tester having a pointed probe tip, the clip has a "U"-shaped configuration formed of first and second moveably connected wire clamping elements which define a recess. The elements are spreadable to accept the wire and biased toward a closed position to retain the wire securely within aligned channels provided for this purpose. Openings extend through the elements and intersect the channels to permit a pointed probe tip to extend through the clip, pierce the wire insulation and contact the wire. Finger grip portions, extending from the elements, may be provided to facilitate spreading of the elements. The clip may be formed of a single flexible molded plastic part or may be two rigid parts, hingedly connected and spring loaded towards the closed position.

Abstract: A method and tool for use with "bed of nails" fixturized automatic test equipment for printed circuit cards for verifying the continuity of component pins with the test nails of the system where the pins of the component are not accessible from the component side of the card. A tool is affixed beneath the component to short out all of the pins thereof and a node accessible from the component side of the board that makes contact with one or more of the pins of the component (such as power or ground) is probed with the continuity probe of the system while a continuity test is performed with respect to each of the test nails associated with the pins and nodes of the component.

Abstract: A system is described for locating faulty integrated circuits on a printed circuit card under the guidance of computer programmed in accordance with the circuit being tested. The disclosed system includes a current pulsing network allowing digital selection, as by the computer, of reference voltage levels at which current is injected into the circuit being tested.

Abstract: A current probe is provided which comprises a handle and a ring of magnetisable material for positioning around an electrical conductor, the ring being split into two portions one being fixed relative to the handle and the other being slidable therewithin between a position in which the ring is closed and a position in which the ring is open. The line of split of the ring is at an angle from the line of sliding movement of the linearly slidable portion. Damping is provided to prevent the slidable portion of the ring from too rapidly moving from a position in which the ring is open to a position in which the ring is closed.

Abstract: By a method of and an apparatus for determining the degree of freshness of fish or other pieces of meat a pair of electrodes of an electrode assembly are brought into contact with the pieces of food, and the degree of freshness is determined electrically by determining the phase angle of the impedance which the tissue of the piece of food in question represents by inducing an alternating current into the tissue of the piece of food and by determining the delay of the voltage produced by the current in relation to the current.

Abstract: Improvements in electrical test probes. The problem with known probes is that degree of penetration into a material being tested is inconsistent and complete penetration of protective coatings is not reliably achieved. The device and method of the invention provide consistent and reliable penetration and electrical contact. Probe assembly (30) includes a probe tip (44) for penetrating a protective coating (4). An off-center punch (42) transmits an axially outward impact force of a predetermined magnitude to tip (44) when tip (44) is urged against coating (4) to move tip (44) axially inwardly against the force of springs (56, 74). The force compressing spring (56) is suddenly released to allow spring (56) to apply an abrupt impact force to tip (44). The degree of impact and penetration may be adjusted for different coating thicknesses by adjusting the stiffness of spring (56).

Abstract: A measuring device housing includes two mutually assembled housing shells having mutually engaged dust protection edges, a trowel shape with a relatively narrow handle-type holder part changing into a relatively wide plate-type indicator part, an operating surface having sides, a switching wheel operating element mounted on the operating surface and extending beyond one of the sides thereof, and another operating element disposed on the operating surface laterally of the switching wheel, the operating elements being disposed within the swinging range of a thumb of the right hand of an operator of the measuring device gripping the holder part from behind for actuating the operating elements.

Abstract: A generator air-gap flux probe for determining rate of change of flux density includes a resilient support spanning the air gap between the stator and the rotor of a dynamoelectric machine to support radial and/or tangential flux coils stably within a short distance of the rotor. The resilient support permits the portion of the flux probe spanning the air gap to deflect substantially during assembly or disassembly of the machine thereby to permit permanent installation of the air-gap flux probe. In one embodiment adapted to longer air gaps, the flux probe is mounted on a pedestal block installed on a dovetail slot wedge in the stator. This reduces the cantilevered distance which the flux probe must span. A tangential flux coil axis stripe marking the axis of the tangential flux coil aids in alignment.

Abstract: A thermometer probe or pyrometer for measuring the temperature in low-convection media is disclosed, which has a temperature-dependent resistor, a receiving sleeve which receives the resistor and a holding device. The resistor is covered by heat conducting material. The receiving sleeve is constructed as an elongated, thin-walled, tubular sleeve of poor heat conducting material and surrounds an elongated air chamber, through which are passed the leads to the temperature-dependent resistor.

Abstract: A hand held voltage sensor in which a low impedance test lamp mode or a high impedance voltage test mode is selectable via a thumb accessed slide switch. In the high impedance mode, three light emitting elements provide indication of the value of voltage potential between a probe conductor and an associated ground conductor being above, below or pulsing above an adjustable threshold level.

Abstract: Measuring apparatus is presented which permits monitoring of current consumption of electronic equipment under operating conditions. The apparatus includes a probe-like element shaped to fit into the equipment fuse holder in place of the cartridge fuse and the cap which holds the fuse in place. A pair of test leads serve to encircuit the contacts within the fuse holder with the terminals of an ammeter. Subsequent to the completion of the monitoring act the probe-like element can be removed and the fuse and cap combination reinserted in the equipment.

Abstract: Testing device for indicating electric voltage, polarity, and for continuity testing, including:two handles connected by a cable and having test prods;high-resistance series resistors connected to the prods;indicating stages having optical indicating elements with staggered voltage ranges in one handle;an oscillator connected to the indicating stages and to an acoustical signal generator;an isolation amplifier connected between the indicating stages and resistors;a battery connected to the amplifier and activatible by the amplifier;a switching power supply connected to the oscillator;an energy storage device connected to the amplifier;a first switch connected to the battery;a second switch connected between the power supply and the storage device for feeding voltage in a rest position, when the storage device is charged and being switchable into contact for feeding a charge to the amplifier and for checking operability in sequence;transistors having bases connected to the oscillator for intermittently switchi

Abstract: This is concerned with a voltage tester of the so-called solenoid type and is more specifically concerned with such a voltage tester which is constructed and arranged to also test the continuity of its leads and prods or contacts.

Abstract: The device is primarily adapted for use in hospitals and comprises a housing having a front window through which a digital display of sensed temperature is observed. The housing may receive one of preferably two probe holsters one of which has associated therewith a probe for oral use and the other of which has a probe for rectal use. Each probe holster is elongated in shape and has a passage for receiving a probe with the probe being fixedly wired into the holster so that the probe cannot be swapped between holsters. A holder is mounted on the top of the device and receives a cartridge of probe covers which are locked into the holder but are easily removed upon insertion of the probe into an individual cover. The holsters and associated probes are constructed to be autoclavable and gas sterilizable. The device is normally stored on a platform through which the batteries in the device are recharged between use of the device. The probe is of improved design and employs a thermistor sensor.

Abstract: A miniature electrical probe is provided with a pair of rotatable elongate tip electrodes for gripping a wire or component lead. In one embodiment, a sliding collar provides an operating mechanism for opening and closing the tips, and in a second embodiment, a lever provides an operating mechanism.

Abstract: According to the invention, a thin wire 13 is arranged across the laser beam 2, and the change of resistance in the thin wire 13 is measured by a resistance meter 21 while moving the thin wire 13 by a driving mechanism 23, thereby to measure the power of the laser beam or the position of the laser beam. The apparatus can be used for monitoring the power of laser beam or position of the same used in the high-power laser device for processing or the like purpose. According to the invention, it is possible to monitor the power and position of the laser without interrupting the laser beam and without incurring substantial increase of the loss of power of the laser beam.

Abstract: A protection circuit for an electronic AC/DC instrument employs an input resistor connected across the DC input terminals of the instrument in series with the inner terminal of a coaxial cable connected to a resistance input probe, the inner cable being connected to the AC input terminals by means of a capacitor.

Abstract: In a probe point device for electrical tests the metallic point proper is carried by a hollow insulating handle or push member on which an insulating head is slidably mounted, spring and abutment means normally maintaining the head at a position of rest at which it wholly covers the point. A fuse cartridge is disposed within the push member to connect the point with the flexible cable provided at the rear of the said member. This cartridge has at its front end an axial indicator button which, when the cartridge blows, acts on a pivoted pawl to engage a first nose thereof into an inner circular groove provided in the head, thus locking the push member with respect to the head at the position of rest. A second tooth of the pivoted point member also locks the push member with respect to the head if the cartridge is missing.

Abstract: An electrostatic system analyzer for checking the voltage at various test points in a high voltage electrostatic spray coating system. The analyzer is in the form of a gun having a telescoping cylindrical barrel with an exposed electrode at its forward end, and a meter at its rearward end, and having a downwardly extending conductive handle. The forward portion of the analyzer body, which is axially and angularly movable relative to the rearward portion, includes a conductive receptacle electrically connected to the electrode, and the rearward, portion of the analyzer body includes four axial bores equidistant from a central axis and equiangularly arrayed thereabout. Each bore contains a resistor, and the resistors are electrically connected in series, with three of the resistors each having an individual plug extending toward the forward analyzer body portion and being receivable for electrical contact within the receptacle when the two portions are telescoped together.

Abstract: A fast risetime, high voltage, high impedance voltage probe utilizes a parallel R-C divider with damping and compensation circuitry to allow measurement of voltage from DC to picosecond pulses. A unique feature of this probe is its construction. The performance of this device is made possible by utilizing microwave chip components on a planar circuit used as the center conductor of a coaxial transmission line.

Abstract: The present invention relates to the design and fabrication of a probe, ancillary signal conditioning circuits with display circuits and related equipment required to measure the resonate frequency and display the shape of the resonance curve. The probe uses the energy absorbing method of indicating these parameters. A graphical display or an analog meter dip indicates the resonant frequency. A digital frequency meter can measures the frequency points precisely.

Abstract: Portable test apparatus utilized to access a field of test points comprises either a single access tool (100) or a multiple access adaptor (200) depending on the mode of testing required. Tool (100) is usually employed for accessing the field to effect aperiodic testing whereas adaptor (200) is generally used for planned test activities.Tool (100) comprises body (111), guide assembly (150) and cover plater (170) which house clamp assembly (130) and pin contact assembly (180). Clamp assembly (130) operates in scissor-like fashion for engaging and disengaging tool (100) from test field grips (401). Spring-loaded pins (181) penetrate apertures (403) within the test field to contact the test points.Adaptor (200) comprises body (211), center panel (240) and guide (260) which enclose pin contact assembly (280); in addition, cam-lever drive assembly (210) attached to body (211). Drive assembly (210) has means for grasping a frame (50) associated with the test field so as to draw body (211) towards frame (50).