Abstract: An energy meter composed of a meter chassis (2) having a transducer (4) connected to sense energy usage and to provide an output having a fixed relation to the sensed energy usage, a replaceable register (6) connectable to the transducer (4) for converting the output provided by the transducer (4) into a readable energy usage indication, a transducer identifying unit (18) secured to the chassis (2) and coded to identify the fixed relation between the transducer output and the sensed energy usage, and a transducer sensing unit (10) secured to the register (6) for coupling with the transducer identifying unit (18) when the register (6) is connected to the transducer (4).

Abstract: Appropriately constructed differential amplifiers are suitable as wideband multiplexers. It is the object of the invention to use such amplifiers in conjunction with a measuring range switch. For this purpose, the differential amplifier is equipped with at least three differential amplifier stages, all of which have a common input and different gain due to different current feedback resistors. The switching is effected through blocking transistors, only one of which is optionally switched on in each case and connects a common current source to the associated differential amplifier stage. The invention can be used in measuring technology for multimeters and oscilloscopes.

Abstract: A wide dynamic range radio-frequency power sensor having a low-power sensor portion and a high-power sensor portion is described. Both sensing portions are connected to an input signal at the same time without the use of a signal splitter. In the preferred embodiment, a single radio-frequency load serves both sensor portions. Each sensor portion has its own output terminal. The low-power sensor portion includes a pair of diodes. The high-power sensor portion (which includes the radio-frequency load) may include a pair of diodes preceded by an attenuator, or a pair of thermocouples.

Abstract: An electronic recording and display apparatus for performing the function of a chart recorder comprises a solid state display device controlled from a memory by a display controller. The memory receives signals in the form of 8-bit binary number digitized by a signal digitizer from an analogue input signal. the display device graphically displays a set of the signals stored in the memory and this can be "scrolled" through all the information stored in the memory in a manner similar to a chart recorder.

Abstract: Calibrating errors of a variable gain amplifier used in an AC calibrator or a meter for measuring AC are determined for a gamut of frequencies. The gain of the variable gain amplifier is varied by adjusting the value of a variable resistor in discrete steps. A variable amplitude signal is applied to the amplifier while the resistor is adjusted in discrete steps so the amplifier derives a gamut of variable amplitude signals that are supposed to have predetermined values. The amplitudes of the gamut of variable amplitude signals derived by the amplifier are detected and compared with the values that the signals are supposed to have to derive a calibrating error signal of the amplifier for each variable resistor value. A gamut of variable frequency, constant amplitude signals is applied to the amplifier while the amplifier gain is constant. The amplifier has a tendency to derive an AC output signal having a different amplitude in response to different ones of the frequencies.

Abstract: A digital level indicating device for use in compact disk players digital audio tape recorders, etc., which includes a converter circuit for converting a digital signal applied thereto to an absolute value signal representative of an absolute value of the digital signal. A peak holding circuit detects and holds a peak of the absolute value signal. A first decoder log-converts the absolute value signal. A second decoder log-converts a signal held by the peak holding circuit. Indicator means display a level of the digital signal in accordance with outputs from both the first and second decoder. A selector switches the choices of resolution of the first decoder and the second decoder.

Abstract: A signal processing device having at least one input for analog input signals and one shift register or a corresponding data memory, an analog/digital converter and a processor for processing the digital signal train forming the output signal of the analog/digital converter, the signal train representing the signal course - which is preferably to be displayed in a display field - wherein the shift register is embodied as a digitally operating high-speed shift register or RAM and is connected to the output side of the analog/digital converter, in particular directly or with a data buffer interposed between them.

Abstract: A signal processing device having a level adapter circuit, in particular a broad band oscilloscope, having an operational amplifier with an amplification factor determined by the ratio of a first resistor between the signal input and the inverting input of the operational amplifier--the virtual ground--and a second resistor between the inverting input of the operational amplifier and the signal output, in which the resistors may optionally be complex, in which at least one parallel resistor is provided for the first resistor, the first terminal of which is firmly connected to the signal input or a connecting point of a plurality of partial resistors forming the first resistor, and the second terminal of which can be switched over between the inverting input of the operational amplifier, which input forms the virtual ground, and the real reference potential for the amplifier input.

Abstract: In this transducer, for converting an analog input signal into an analog output signal whose level corresponds to the level of the analog input signal, there are included: an A/D converter for converting the analog input signal into a digital signal; an input device comprising a plurality of switches; an upper limit setting means for setting an upper limit value for the analog input signal, according to operation of the switches; a lower limit setting means for setting a lower limit value for the analog input signal, according to operation of the switches; a storage device, for storing a current value of the digital signal output by the A/D converter; a comparison means for comparing the current value of the digital signal output by the A/D converter as converted from the analog input signal, and the upper limit value and the lower limit value, all of which are stored in the storage device; an output means for producing an output when the comparison executed by the comparison means indicates that the current

Abstract: Apparatus for measuring current over a wide range generates an eight bit accurate, 16-bit dynamic range digital signal from a current transformer secondary. Two signals proportional to the rectified secondary current, one generated by a large burden resistor and the other by an amplifier with programmable gain and an overrange indication, are applied through a multiplexer to an eight bit analog to digital converter which has three selectable reference voltages. A microprocessor selects the input signal, converter reference voltage, and one of four levels of amplifier gain which provide the greatest resolution for the magnitude of the current being measured, and provides an appropriate scale factor, from 2.sup.0 to 2.sup.8, for the eight bit accurate digital signal generated by the analog to digital converter.

Abstract: A probe for sensing radio frequency power, utilizing two independently-driven radio frequency-sensitive diodes. The two diodes are driven through a common RF input, through a branch network which separates and feeds the probe RF power to each diode independently. The diodes are unequally padded from the RF input, to provide an extended sensitivity range for the probe. One diode, therefore, operates in a lower dBm range, while the other diode operates in a higher dBm range. Two separate outputs are provided from the probe to supply a common power meter which monitors the appropriate output for the present power level of the radio frequency input.

Abstract: A digital level indicating device for use in compact disk players digital audio tape recorders, etc., which includes a converter circuit for converting a digital signal applied thereto to an absolute value signal representative of an absolute value of the digital signal. A peak holding circuit detects and holds a peak of the absolute value signal. A first decoder log-converts the absolute value signal. A second decoder log-converts a signal held by the peak holding circuit. Indicator means display a level of the digital signal in accordance without puts from both the first and second decoder. A selector switches the choices of resolution of the first decoder and the second decoder.

Abstract: A waveform measuring device includes a variable color display for exhibiting a measured waveform. The portions of the exhibited waveform that are within predetermined limits are illuminated in a first color, and the portions of the exhibited waveform that are outside the limits are illuminated in a second color.

Abstract: A meter is provided which visually displays and audibly announces values which are detected. A switch is manually operated to maintain the visual representation until the audible announcement has been generated.

Abstract: An automatic gain setting circuit for automatically adjusting the gain of an amplifier which drives an analog meter. The gain of this amplifier is adjusted automatically with the push of a button switch so that the meter will read mid-range for the signal input to the amplifier. In this circuit, the operational amplifier is connected between an input signal and the analog meter readout. This operational amplifier utilizes a feedback circuit having a variable resistance which changes the gain of the amplifier as the resistance is changed. The resistance in this feedback circuit is changed by an electrical comparison circuit which compares the output signal from the amplifier with a reference voltage upon the push of a button switch. The reference voltage is preset to cause the meter to read mid-range. Once the button switch is pushed, the comparison circuit provides an output control signal which is directed to the feedback circuit of the operational amplifier.

Abstract: This apparatus and method permit plotting a series of data values at an optimum scale expansion, even when the largest value is not known in advance, for permanent recording or transitory display. In response to each data value several display signals are derived, corresponding to representation of that data value at several different scale expansions. These several signals are used to position respective indicia on a visually readable medium. If desired the several display signals may all be recorded, as for example on magnetic tape, and the acutal plotting (i.e., production of indicia) performed later. The data-value magnitude is represented by respective displacements of the indicia in one direction from a baseline, at the several scale expansions. Thus indicia are produced for all of the scale expansions that correspond to on-scale positions. The medium moves relative to the indicia-producing apparatus, along a second, orthogonal direction.

Abstract: A combined electrical and optical channel for use in an oscilloscope is provided in which the vertical deflection factor is set by a single input attenutation selector switch. The electical input is passed through an attenuator. The optical input is passed through an input transimpedance amplifier having at least two gain modes and an attenuator. The output from the input attenuation selector switch is encoded to form a digital output. The attenuators for the electrical channel are driven directly by the input attenuation selector switch or by the digital output corresponding to the setting of the input attenuation selector switch. The digital output is also decoded by a logic block to generate a gain mode logic signal to switch the gain modes of the input transimpedance amplifier.

Abstract: A method and apparatus for fixing an instantaneous measured value performs the steps of creating measured values as a mean value of a set number of individual measurements, recording sequential measured values after initialization in a cycle determined by a flow control, checking with a control device if a new measured value exceeds a base value and if the difference between the two latest measured values lies within a given limit range, before fixing the respective new measured value, and checking with the control device if the difference between the individual values resulting from the latest two individual measurements lies within the given limit range and if a fixing of the last measured value and/or individual value takes place when the differences between the mean values and the differences between the individual values lie in the respective given limit range.

Abstract: A digital panel meter adapted for replacement of a standard analog panel meter and designed to selectively receive different ranges of input signals such as AC or DC input signals. The meter circuitry employs an analog-to-digital converter having multiple digits, an input circuit including a range circuit, an operational amplifier and filter circuitry. A relay is tripped for signaling the attaining of a trip point. An audible alarm is provided that may be enabled or disabled and that may be operated in either continuous or short term modes.

Abstract: A solid-state watthour meter for registering AC electrical energy consumption by a load connected to a source of AC load current and AC line voltage includes a voltage sensing transducer for producing a signal corresponding to the line voltage and a current sensing transducer for producing a signal corresponding to the load current. A solid-state measurement circuit receives the voltage and current signals as its inputs and produces an output signal corresponding to the AC electrical energy consumption of the load. A power supply, including a regulator circuit having a calibration resistor, provides a DC voltage to the measurement circuit. The DC voltage across the regulator circuit is dependent on the impedance of the calibration resistor. The measurement circuit includes apparatus for relating the registration of the meter to the DC supply voltage. The calibration resistor is readily removably electrically connected in the regulator circuit.

Abstract: Attenuator having a high input impedance and several switching levels for high frequencies and oscilloscope and active probe comprising such an attenuator. A high frequency attenuator (15) having a high input impedance and several switching stages intended to attenuate a high-frequency electric signal introduced at an input terminal (10) of the attenuator. The attenuator supplies at a low-impedance output terminal (11) an output signal corresponding to the attenuated input signal. The attenuator comprises k broadband amplifiers A.sub.n (1.ltoreq.n.ltoreq.k) having a very small input capacitance, capacitances D.sub.n arranged between each input and each output of each amplifier, and capacitances C.sub.n arranged between each input of each amplifier and the input terminal of the attenuator. The accurate attenuation switching levels are obtained by using different ratios C.sub.n /D.sub.

Abstract: A digital voltmeter includes a display device surrounded by a variable color background area for indicating measured voltage in a digital format. The color of the background area is controlled in accordance with the significance of measured voltage.

Abstract: An instrument has a crossed-coil-type movable magnet in which a movable magnet rotatable about the shaft of a pointer needle is installed in a crossed coil unit and a measured quantity or the like is operated by supplying electric power to the crossed coil unit. The instrument includes an input unit to receive an input from a measurement object to be measured, an arithmetic section or ROM to set directions and time values for supplying electric current to the coils of the crossed coil unit, and a circuit section to deliver pulse signals with predetermined potential values to the crossed coils under conditions associated with the directions and time values, to provide a very broad angular range of the pointer needle.

Abstract: An indicator monitor which performs a plurality of functions. Both engine exhaust gas temperature and engine rpm are monitored. Based on the engine rpm, it is determined whether the engine is in starting or operating condition. Different parameters and different values are used based on this indication. A plurality of different functions including parameters indicative of temperature in rpm can be monitored by this one meter with a single display and which has electronics that can be housed in an area smaller than the display face.

Abstract: A voltmeter includes a variable color analog display for providing an analog indication of the value of a measured signal in a color in accordance with the relation of the measured value to predetermined limits.

Abstract: An electronic interface device is provided for use between a sensor and a display unit, including a controllable generator which delivers a signal to the display unit and is connected to an input of a comparator whose other input receives the output signal of the sensor. The output of the comparator controls the up counting or the down counting of an up-down counter of clock pulses. The sign output of the up-down counter controls the generator.

Abstract: A digital voltage and continuity test instrument for use by electricians is disclosed. AC, DC and continuity test functions are provided with the AC and DC test modes including auto-zeroing. In a continuity test mode the continuity of the probe leads or the continuity of a circuit may be detected and indicated with a zero-display value. With the probes open circuit in the continuity mode the display provides a reading proportionate to the battery voltage level of the instrument. The electrical test circuitry includes a resistive divider network connected between the test probes, an AC rectifier for demodulating AC voltages received from the resistor divider network and an analog to digital convertor for receiving DC voltages from the resistive divider network or from the demodulator for driving the display according to the magnitude of the received voltage. Strain relief is provided for the test leads and includes an eyelet having a first washer-like end and a second tubular portion for receiving a test lead.

Abstract: A digital measuring method an apparatus for displaying quasi-analog measured values performs the steps of displaying a measurement scale and interconnected triggerable indicator segments on a display having a given indicator center distance, representing a measured value to be indicated by the position of the indicator segments, controlling the resolution of the quasi-analog measured value display in dependence of the number of indicator segments triggerable within a measurement period to be represented, setting the resolution substantially lower than a resolution with which an A/D converter connected to the display operates, and subjecting a control command for triggering an actual indicator segment to a hysteresis, which assures that a switchover from a previous indicator segment to an actual indicator segmet does not take place until the actual measured value has increased or decreased by substantially more than one-half the given indicator center distance.

Abstract: In order to display a measured value, a digital measuring instrument is provided with a digital display and an analog display. The display value emitted by the digital display is fixed during a predetermined holding time. The analog display displays the difference between the current measured value and the particular display value of the digital display at the time. The current measured value may be read off at the beginning of a new holding time on the digital display, or it can be ascertained as the sum of the values of the digital and analog displays.

Abstract: A method for locking scales to a waveform display uses reference points from the waveform to determine starting scale points. Based upon the starting scale points and the characteristics of the waveform the scales are calculated. Any changes in gain in the waveform are applied to the scales so that the scales change in direct proportion to the waveform. The field/line numbers of a television video signal are tracked and displayed on the waveform display to identify that portion of the waveform relative to a picture frame which is being displayed.

Abstract: An oscilloscope having a displayed trigger indicator is provided in which triggering level, slope, and source information on displayed directly on the viewing screen adjacent corresponding waveforms. In a preferred embodiment, a vertical bar represents the triggering level range, and a marker or dot is superimposed thereon to indicate the trigger level. Slope polarity is also indicated, as is triggering source. These indicators permit the triggering point to be quickly selected and set while viewing them in relationship to corresponding waveforms, and are always on screen for convenient reference and waveform photography.

Abstract: A digital measuring device for a quasi-analog measurement value indication includes a display for the measurement value indication, a pre-determined overall measuring range disposed on the display, a measurement value scale forming a spread measuring range section of the overall measuring range with variable spreading, the measuring value scale being addressable in planar segments with alpha numeric characters, an indicating device for indicating a value on the measuring value scale, and an automatic control placing measurement values within the displayed measuring range section with numerically displayed scale values fitting the measuring range section, with the overall measuring range remaining constant and the measuring range section having a selected spreading factor.

Abstract: A digital oscilloscope includes an amplifier having adjustable gain and offset for producing an output signal in response to an input signal, a triggering system for producing a trigger status signal when the amplifier output signal reaches an adjustable trigger level, and a digitizer for generating a waveform data sequence representing magnitudes of samples of the amplifier output signal acquired at various times with respect to assertion of the trigger status signal. The oscilloscope produces a waveform display on a screen according to the waveform data sequence produced by the digitizer and automatically adjusts the amplifier gain and offset, the trigger level, and the sampling rate of the digitizer so that the waveform data produced by the digitizer provides for a waveform display suitably representative of the time dependent behavior of the input signal.

Abstract: An attenuator useful in measuring low level leakage currents is disclosed. The attenuator includes a plurality of current dividers coupled in cascade. Each current divider includes an input and two outputs between which the current entering the input is divided. The current exiting the last divider is significantly attenuated from that entering the attenuator. The attenuator output is coupled to the device under test and to one input of a differential amplifier. A known current is input to the differential amplifier and part is directed to the attenuator input and the other part to a current measuring device. The difference between the known current input to the differential amplifier and that measured is the current input to the attenuator. In the steady state, the current input to the differential amplifier from the current attenuator is about zero.

Abstract: A measurement circuit is operative with an electric measurement transmitter, particularly an NTC-resistor (1), and an indicating instrument (3) which has a display which is dependent on a transmitter voltage of the measurement transmitter. The circuit is developed for the suppressing of variations in the display within a middle measurement range. For this purpose, the measurement circuit has a clamping circuit (10-19). The clamping circuit permits the indicating instrument to be acted on within a lower measurement range (up to 80.degree. C.), up to a first limit transmitter voltage by a voltage, which is varied as a function of the transmitter voltage. In a middle measurement range (80.degree. C. to 105.degree. C.) between the first limit transmitter voltage and a second limit transmitter voltage, the clamping circuit feeds the indicating instrument (3) with a constant voltage, which is equal to the voltage present on the indicating instrument at the first limit transmitter voltage.

Abstract: A master metering module is taught which utilizes a programmed microprocessor and externally operated switches to alert the module as to what kind of system is being monitored thereby. For example, is the system being monitored a .DELTA.-connected electrical system or a Y-connected electrical system. This is useful in providing output indications of line-to-line voltage or line-to-neutral voltage, for example. When measuring voltages whether line-to-line or line-to-neutral one voltage value is substituted from another. A differential amplifier is utilized to do this. In one case the differential amplifier subtracts one line voltage from another line voltage, but in another case it subtracts neutral or zero ground potential from a line voltage. A switching arrangement is provided which interconnects one terminal of the differential amplifier with the neutral input terminal and with a line input terminal through appropriate conditioning of the microprocessor.

Abstract: The stimulus signal for an induced polarization logging system is presented to the formation intermittently, alternately being applied and removed as a square wave of alternating polarity, and the response signal amplification level is time gated with the stimulus signal.

Abstract: A measuring symbol driving circuit drives the measurement symbols on a liquid crystal display in a digital multimeter. This measuring symbol driving circuit includes a rotary measuring range changeover switch which selects the respective measuring symbols to be displayed. A control signal generating circuit receives the backplane pulse signal supplied to the common electrode of the liquid crystal display, and phase inverts this signal through the use of an exclusive OR gate in order to develop a control signal supplied to the measuring symbol selected by the measuring range changeover switch. Further, the driving circuit includes a circuit for monitoring the presence of a short circuit between the input jack and common electrode of the digital multimeter to selectively display a short circuit indicator symbol.

Abstract: A device for quantified analog display, with planar structure, and measurement apparatus with multiple ranges and multiple operating modes using this display, which visualizes in analog form a value of a selected measured quantity among several. The display device comprises a flat substrate (2), a succession of identical electrodes (6) arranged side by side on one face of the substrate, and selectively excitable, and with at least one graduated scale (7) adjacent to the succession of identical electrodes (6) to determine the value of the measured quantity, in combination with at least one electrode of the succession of identical electrodes.

Abstract: A metal detector circuit includes a transmit coil (12) and a receive coil (56) arranged in a balanced induction configuration in an electromagnetic field. The receive signal from the receive coil (56) is input to electronic switches (146, 148) which receive quadrature reference inputs from a phase shift circuit (112). The phase demodulated outputs of the switches (146, 148) are passed through amplifiers and input to an analog-to-digital converter (324) to produce digital signal samples which are transmitted through a bus (326). The bus (326) is connected to random access memory (414, 416) and a read only memory (418) which includes a stored signal processing program. A microprocessor (374) is connected to the bus (376) for receiving the digital signal samples and the stored program from memory (418). The microprocessor (374) executes the stored signal processing program to produce a digital output signal which is transmitted through the bus (326) to a digital-to-analog converter (360).

Abstract: An apparatus for measuring low currents with high dynamics, comprising in series: a multi-range preamplifier, a logarithmic amplifier, a thresholding circuit, an alarm circuit and a reading circuit, the preamplifier comprising in series: a first differential amplifier receiving at its inverting input the low current to be measured and a second amplifier, the first amplifier having a linear feedback chain of very high impedance and the second amplifier having a linear feedback chain of much lower impedence, a zero point adjustment and a circuit for testing the gain of the apparatus being also provided on the first amplifier.

Abstract: A temperature measuring circuit which includes a primary temperature sensor such as a thermocouple, an external source for generating predetermined temperature modifying signals, and a signal combining circuit for combining the modifying signals with the temperature sensor signal to generate a modified output signal and display thereof.

Abstract: A portable battery powered tone source with a built-in audio cable tester. Plural outputs consist of -40 dB, mic level; -10 dB line level and 1W speaker level. Continuity in the system under test from input to speakers causes an audio frequency signal to be present at speakers. This systems own speakers can be used as monitors in the testing process. Moving the device (source) enables the user to audibly locate the point at which the continuity starts/stops. At such time the user can test the audio castle at that point. The various plugs of the device are compatible with all common audio jacks enabling the user to test all types of audio equipment as well as all types of audio cables with only one device. The device can also be used to test any direct point-to-point connection such as common ground or a PC board run with a simple test lead adaptor.

Abstract: An ac measuring instrument automatically compensates an input attenuator to achieve precision frequency response. The output of the input attenuator is applied to both the conventional measurement portion of the instrument and to an amplifier of variable gain. The output of the variable gain amplifier drives either a resistive or capacitive impedance coupled to the output of the input attenuator. The impedance is thus driven by a voltage that is a scaled replica of the output of the input attenuator. That scale factor may vary from near zero to greater than one, and the impedance acts as a virtual trimmer whose apparent value varies as the scale factor of its actual value according to the gain established for the variable gain amplifier. The proper gain therefor is determined by a servo loop that applies a test pulse to the input attenuator and subsequently samples the output thereof at least twice.

Abstract: In order to maintain the torque of the ratio meter and the drive of amplifiers feeding it independently of the amplitudes of a sine signal voltage and a cosine signal voltage, a regulation is provided. The regulation makes use of two-quadrant voltage-controlled sources of current each of which is connected to a coil branch. Control voltage amplifiers, one connected in front of each source of current, are furthermore used. A sum-current resistor is provided to form the sum of the supply currents of two voltage-controlled sources of current. The supply currents represent the amounts of the sine signal voltage and cosine signal voltage which act on the voltage amplifiers. From the resistor for the formation of the sum of the supply currents a signal is derived which switches the amplification of the voltage amplifiers automatically in the direction of compensation.

Abstract: Apparatus is provided for simultaneously measuring and displaying voltage, current and frequency in a polyphase alternating current system. The apparatus is operable in either a line-to-line or a line-to-neutral measuring mode without rewiring the apparatus to the measured system. A logic circuit is selectively operated to connect the appropriate voltage lines associated with each phase of the system to the apparatus and LEDs associated with each phase light to indicate the phase selected for measurement. Multi-digit seven segment LED displays are provided for simultaneously indicating the voltage, current and frequency measured.

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: A capacitance measuring device having an astable multivibrator, a monostable multivibrator, a metering circuit and an overrange circuit. The astable multivibrator generates a repetitive series of evenly spaced pulses which are received by the monostable multivibrator to which a capacitor of unknown value is connected. Each of the pulses initiating a voltage output in the monostable multivibrator which remains in the high state for a length of time linearly proportioal to the value of the unknown capacitor. Thereafter, the voltage output of the monostable multivibrator reverts to the low state and remains at the low state until it receives the next one of the repetitive pulses. The metering means averages the high and low states of the voltage output and provides a pair of average voltage readings indicative of capacitance value of the unknown capacitance.

Abstract: An electrostatic system analyzer for checking the voltage at various test points in a high voltage electrostatic spray coating system. The analyzer includes an elongated analyzer body housing several elongated high voltage resistors making up a high resistance path. One end of the high resistance path is coupled to an ammeter mounted at a proximal end of the analyzer body, and the other end of the resistance path is coupled to an electrode mounted on a fitting at the distal end of the analyzer body. The fitting is rotatably mounted on the analyzer body and is generally L-shaped to position the electrode to be laterally offset from the distal end of the analyzer body. This positioning of the electrode facilitates viewing the electrode when it is placed at test points in the electrostatic coating system. The ammeter has a meter face which includes a different scale related to each test point, with the scales being offset from one another to compensate for resistance differences between the test points.

Abstract: A multi-probe metering apparatus is characterized by a central unit (I) comprising various signal processing circuits and modules (II) having two gates (A, B) to which are connected various pick-ups (III). The central unit (I) communicates with the module (II) via a numerical signal link (10) for the transmission of pick-up identification signals, and by two analogue links (9, 9b) permitting simultaneous connection of two pick-ups.