Abstract: An alternating voltage detector having a sensor for the detection of an electric alternating field, an electrical signal transducer connected to the sensor for signaling an electrical alternating field detected by the sensor, and an indicator unit connected to the electrical signal transducer for the indication of the signaled electrical alternating field, has an interference pulse filter arranged between the sensor and the electrical signal transducer which filters out electrical pulses or pulse packets detected by the sensor which have an average pulse duration or average pulse packet duration less than a predetermined time.

Abstract: A test device is described for testing an electromagnetic quantity, such as a voltage or a magnetic field. The test device includes a housing, a sensor arranged in the housing and sensing the electromagnetic quantity, a processing circuit for processing to signals received from the sensor, display elements for displaying the signals processed by the processing unit, a galvanic element for supplying power to the test device, an illuminator for illuminating an area to be tested, and a switch for activating the illuminator. The test device has a small footprint and does not require an external light source even under difficult lighting conditions.

Abstract: Alternating voltage detector

Abstract: In a first measurement step, the two test probes of a measurement apparatus are contacted with two of the three phase lines. The measurement apparatus determines the frequency of the three-phase voltage. In a subsequent second measurement step, one of the two test probes is brought into connection with the remaining third phase line. The other test probe is held in contact with the other line. In the second measurement step the voltage level or voltage profile on the third phase line is evaluated inside the measurement apparatus in comparison to the first phase line during one or more time windows of length .pi..

Abstract: The invention relates to an instrument for testing and/or measuring electric magnitudes, in particular voltages and/or resistances. The instrument consists of two handle parts (10, 12), which are connected by a flexible cable (14), and which each have a contact point (16, 18). In addition to the contact point (16, 18), the handle parts (10, 12) each have a receptacle for the contact point (18, 16) of the other handle part (12, 10). The handle parts (10, 12) can be plugged together in such a way that their contact points (16, 18) each are pluggable into the receptacle of the other handle part (12, 10) nonparallel with the contact point (18, 16) of such other handle part. The contact point (16) and the receptacle of the one handle part (10) are arranged in a down-folding point part (22), so that the instrument, in the plugged-together condition, can be folded together for convenient, safe and space-saving storage.

Abstract: A phase sequence indicator with two measuring contacts for contacting with connections of the object to be measured has a grouring contact touchable by the user, an evaluation circuit connected to the measuring contacts and the grounding contact, and an indicating device controlled by the evaluation circuit for indicating the direction of the rotary field. The evaluation circuit has a voltage-testing circuit for detecting the value of the voltage occurring between the measuring contacts, and the indicating device comprises additional indicating elements for indicating the value of the voltage.

Abstract: A process and apparatus for locating and identifying electrical lines in which a high frequency carrier wave, modulated with a four-bit, serial binary code, is transmitted down the line. An electro-magnetic detector is used to locate the particular line bearing this modulated wave, permitting identification of the line without having to make actual electrical contact with the line at the point of identification.

Abstract: A testing device for single-pole voltage testing comprises, between a test electrode (1) and a ground electrode (2), a high impedance dropping resistor (R1) and a measurement resistor (R2) connected in series. The ground electrode (2) is capacitively coupled to earth through the body of the user. The value of the dropping resistor (R1) is at least 10 times greater than the maximum variation which occurs in the capacitively coupled reactance (C1, C2) of the user relative to the ground, so that the total impedance is almost constant. The voltage drop across the measurement resistor (R2) is amplified, rectified and compared in a comparison circuit with predetermined reference voltages in order to control a light emitting diode indicator (D2, D3, D4, D5) corresponding to the measured voltage. The test device can also be constructed for contactless voltage testing or can also be used as a continuity tester.

Abstract: A device for measuring the shading of a translucent pane having an exterior side and an interior side comprising first and second photoelectric sensors for measuring unattenuated daylight, each of the sensors having a photosensitive surface and a spectral sensitivity substantially corresponding to the spectral sensitivity of the human eye and generating an output signal proportional to the intensity of the measured daylight, a first mounting element for mounting the first sensor on the exterior surface with the photosensitive surface of the first sensor facing away from the exterior surface, a second mounting element for mounting the second sensor on the interior surface with the photosensitive surface of the second sensor facing the interior surface, a housing, and an electronic circuit disposed in the housing and electrically connected to the first and second sensors for calculating the difference of the output signals of the first and second sensors, calculating the ratio of the difference to the signal fr