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57-629: [REDACTED] Look up scope  or -scope in Wiktionary, the free dictionary. Scope or scopes may refer to: People with the surname [ edit ] Jamie Scope (born 1986), English footballer John T. Scopes (1900–1970), central figure in the Scopes Trial regarding the teaching of evolution Arts, media, and entertainment [ edit ] CinemaScope or Scope prints, anamorphic film prints Scope (magazine) ,

114-475: A 1 cm grid with closer tick marks (often at 2 mm) on the centre vertical and horizontal axis. One expects to see ten major divisions across the screen; the number of vertical major divisions varies. Comparing the grid markings with the waveform permits one to measure both voltage (vertical axis) and time (horizontal axis). Frequency can also be determined by measuring the waveform period and calculating its reciprocal. On old and lower-cost CRT oscilloscopes

171-474: A 1925 US legal case in Tennessee SCOPE Act , a 2023 Texas internet law See also [ edit ] Scope creep , the incremental expansion of the scope of a project Scopus (disambiguation) Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title Scope . If an internal link led you here, you may wish to change

228-403: A 50 Ω signal source or used with Z 0 or active probes. Less-frequently-used inputs include one (or two) for triggering the sweep, horizontal deflection for X‑Y mode displays, and trace brightening/darkening, sometimes called z'‑axis inputs. Open wire test leads (flying leads) are likely to pick up interference, so they are not suitable for low level signals. Furthermore, the leads have

285-463: A 9 megohm series resistor shunted by a low-value capacitor to make an RC compensated divider with the cable capacitance and scope input. The RC time constants are adjusted to match. For example, the 9 megohm series resistor is shunted by a 12.2 pF capacitor for a time constant of 110 microseconds. The cable capacitance of 90 pF in parallel with the scope input of 20 pF and 1 megohm (total capacitance 110 pF) also gives

342-474: A South African men's magazine The Scope (alternative weekly) , a newspaper in St. John's, Newfoundland Scope (Australian TV series) Scope (Irish TV series) Scope (album) , a 1979 studio album by Buck Hill Quartet Computing [ edit ] Scope (computer science) , the range in which a variable can be referenced scope ( scopeArchiv ), an archival information program CDC SCOPE ,

399-424: A barrier disc keeps the user's fingers away from the point being examined. Maximum voltage is in the low tens of kV. (Observing a high voltage ramp can create a staircase waveform with steps at different points every repetition, until the probe tip is in contact. Until then, a tiny arc charges the probe tip, and its capacitance holds the voltage (open circuit). As the voltage continues to climb, another tiny arc charges

456-400: A fast analog multiplier, and provided a display of the product of the input channels. Multiple-trace oscilloscopes have a switch for each channel to enable or disable display of the channel's trace. These include controls for the delayed-sweep timebase, which is calibrated, and often also variable. The slowest speed is several steps faster than the slowest main sweep speed, though the fastest

513-461: A fixed offset of interest, or changes slowly, the user will usually prefer "DC" coupling, which bypasses any such capacitor. Most oscilloscopes offer the DC input option. For convenience, to see where zero volts input currently shows on the screen, many oscilloscopes have a third switch position (usually labeled "GND" for ground) that disconnects the input and grounds it. Often, in this case, the user centers

570-536: A focusing anode within the CRT. Flat-panel displays do not need this control. This adjusts trace brightness. Slow traces on CRT oscilloscopes need less, and fast ones, especially if not often repeated, require more brightness. On flat panels, however, trace brightness is essentially independent of sweep speed, because the internal signal processing effectively synthesizes the display from the digitized data. This control may instead be called "shape" or "spot shape". It adjusts

627-704: A global emerging art fair SCOPE Maastricht , a nonprofit study association at Maastricht University, The Netherlands Scientific Committee on Problems of the Environment Senior Consulting Program for Engineering, a program at Olin College in Massachusetts Other uses [ edit ] Scope (horse) , a racehorse Scope (mouthwash) Norfolk Scope , an arena in Norfolk, Virginia Scopes trial ,

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684-519: A high inductance, so they are not suitable for high frequencies. Using a shielded cable (i.e., coaxial cable) is better for low level signals. Coaxial cable also has lower inductance, but it has higher capacitance: a typical 50 ohm cable has about 90 pF per meter. Consequently, a one-meter direct (1×) coaxial probe loads a circuit with a capacitance of about 110 pF and a resistance of 1 megohm. To minimize loading, attenuator probes (e.g., 10× probes) are used. A typical probe uses

741-401: A knob in front of the calibrated selector knob) offers uncalibrated speeds, typically slower than calibrated. This control provides a range somewhat greater than the calibrated steps, making any speed between the steps available. Some higher-end analog oscilloscopes have a holdoff control. This sets a time after a trigger during which the sweep circuit cannot be triggered again. It helps provide

798-416: A magnifying optical instrument used to see objects that are too distant for the naked eye Spotting scope , a portable high-power telescope for observation of distant objects Telescopic sight , a telescope used as a sighting device, typically on rifles and air rifles Organisations [ edit ] Scope (charity) , a British charity that supports people with disabilities SCOPE Art Show ,

855-449: A mode switch to select either channel alone, both channels, or (in some) an X‑Y display, which uses the second channel for X deflection. When both channels are displayed, the type of channel switching can be selected on some oscilloscopes; on others, the type depends upon timebase setting. If manually selectable, channel switching can be free-running (asynchronous), or between consecutive sweeps. Some Philips dual-trace analog oscilloscopes had

912-458: A number of viewing instruments SCOPE (protein engineering) , a technique of creating gene libraries Scope (synthesizer) , a DSP-based synthesizer by Creamware Endoscope , an optical instrument (borescope) used to perform medical visual inspection (endoscopy) of enclosed body cavities. The term "scope" may refer to the following medical procedures: Arthroscopy , for examining a joint space (orthopedics) Bronchoscopy , for examining

969-400: A selected point on the signal, providing a stable display. In this way, triggering allows the display of periodic signals such as sine waves and square waves, as well as nonperiodic signals such as single pulses, or pulses that do not recur at a fixed rate. With triggered sweeps, the scope blanks the beam and starts to reset the sweep circuit each time the beam reaches the extreme right side of

1026-533: A series of Control Data Corporation operating systems Concepts [ edit ] Scope (logic) , the range influenced by the quantification in logic Scope (formal semantics) , the natural language counterpart of logical scope Scope (project management) , the sum of all projects, products and their features Scope of practice (US and Canada), terminology that defines the procedures, actions, and processes that are permitted for licensed professionals Devices and procedures [ edit ] Any of

1083-440: A single person to carry. In addition to portable units, the market offers a number of miniature battery-powered instruments for field service applications. Laboratory grade oscilloscopes, especially older units that use vacuum tubes , are generally bench-top devices or are mounted on dedicated carts. Special-purpose oscilloscopes may be rack-mounted or permanently mounted into a custom instrument housing. The signal to be measured

1140-418: A stable display of repetitive events in which some triggers would create confusing displays. It is usually set to minimum, because a longer time decreases the number of sweeps per second, resulting in a dimmer trace. See Holdoff for a more detailed description. To accommodate a wide range of input amplitudes, a switch selects calibrated sensitivity of the vertical deflection. Another control, often in front of

1197-433: A thermionic emitter in 1931. This stable and reproducible component allowed General Radio to manufacture an oscilloscope that was usable outside a laboratory setting. After World War II surplus electronic parts became the basis for the revival of Heathkit Corporation , and a $ 50 oscilloscope kit made from such parts proved its premiere market success. An analog oscilloscope is typically divided into four sections:

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1254-444: A time constant of 110 microseconds. In practice, there is an adjustment so the operator can precisely match the low frequency time constant (called compensating the probe). Matching the time constants makes the attenuation independent of frequency. At low frequencies (where the resistance of R is much less than the reactance of C ), the circuit looks like a resistive divider; at high frequencies (resistance much greater than reactance),

1311-461: A trigger, and the slope switch selects positive-going or negative-going polarity at the selected trigger level. To display events with unchanging or slowly (visibly) changing waveforms, but occurring at times that may not be evenly spaced, modern oscilloscopes have triggered sweeps. Compared to older, simpler oscilloscopes with continuously-running sweep oscillators, triggered-sweep oscilloscopes are markedly more versatile. A triggered sweep starts at

1368-404: A visible display, the beam finder circuit overrides any blanking and limits the beam deflection to the visible portion of the screen. Beam-finder circuits often distort the trace while activated. The graticule is a grid of lines that serve as reference marks for measuring the displayed trace. These markings, whether located directly on the screen or on a removable plastic filter, usually consist of

1425-406: Is advancing, delayed sweep only, or (on some) a combination mode. Good CRT oscilloscopes include a delayed-sweep intensity control, to allow for the dimmer trace of a much-faster delayed sweep which nevertheless occurs only once per main sweep. Such oscilloscopes also are likely to have a trace separation control for multiplexed display of both the main and delayed sweeps together. A switch selects

1482-434: Is fed to one of the input connectors, which is usually a coaxial connector such as a BNC or UHF type . Binding posts or banana plugs may be used for lower frequencies. If the signal source has its own coaxial connector, then a simple coaxial cable is used; otherwise, a specialized cable called a " scope probe ", supplied with the oscilloscope, is used. In general, for routine use, an open wire test lead for connecting to

1539-406: Is generally the same. A calibrated multiturn delay time control offers wide range, high resolution delay settings; it spans the full duration of the main sweep, and its reading corresponds to graticule divisions (but with much finer precision). Its accuracy is also superior to that of the display. A switch selects display modes: Main sweep only, with a brightened region showing when the delayed sweep

1596-427: The CRT, was known in 1897, and in 1899 Jonathan Zenneck equipped it with beam-forming plates and a magnetic field for deflecting the trace, and this formed the basis of the CRT. Early CRTs had been applied experimentally to laboratory measurements as early as the 1920s, but suffered from poor stability of the vacuum and the cathode emitters. V. K. Zworykin described a permanently sealed, high-vacuum CRT with

1653-659: The Wikimedia System Administrators, please include the details below. Request from 172.68.168.237 via cp1104 cp1104, Varnish XID 181740590 Upstream caches: cp1104 int Error: 429, Too Many Requests at Thu, 28 Nov 2024 05:34:50 GMT Oscilloscope Oscilloscopes are used in the sciences, engineering, biomedical, automotive and the telecommunications industry. General-purpose instruments are used for maintenance of electronic equipment and laboratory work. Special-purpose oscilloscopes may be used to analyze an automotive ignition system or to display

1710-475: The Y-plane as the more positive Y-plates will attract the beam. This control may be absent from simpler oscilloscope designs or may even be an internal control. It is not necessary with flat panel displays. Modern oscilloscopes have direct-coupled deflection amplifiers, which means the trace could be deflected off-screen. They also might have their beam blanked without the operator knowing it. To help in restoring

1767-399: The calibrated selector knob, offers a continuously variable sensitivity over a limited range from calibrated to less-sensitive settings. Often the observed signal is offset by a steady component, and only the changes are of interest. An input coupling switch in the "AC" position connects a capacitor in series with the input that blocks low-frequency signals and DC. However, when the signal has

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1824-436: The circuit looks like a capacitive divider. The result is a frequency compensated probe for modest frequencies. It presents a load of about 10 megohms shunted by 12 pF. Such a probe is an improvement, but does not work well when the time scale shrinks to several cable transit times or less (transit time is typically 5 ns). In that time frame, the cable looks like its characteristic impedance, and reflections from

1881-410: The core provides a current into an appropriate load, and the voltage across that load is proportional to current. This type of probe only senses AC. A more-sophisticated probe includes a magnetic flux sensor ( Hall effect sensor) in the magnetic circuit. The probe connects to an amplifier, which feeds (low frequency) current into the coil to cancel the sensed field; the magnitude of the current provides

1938-571: The display sidewise. It usually sets the left end of the trace at the left edge of the graticule, but it can displace the whole trace when desired. This control also moves the X-Y mode traces sidewise in some instruments, and can compensate for a limited DC component as for vertical position. Each input channel usually has its own set of sensitivity, coupling, and position controls, though some four-trace oscilloscopes have only minimal controls for their third and fourth channels. Dual-trace oscilloscopes have

1995-415: The display, vertical controls, horizontal controls and trigger controls. The display is usually a CRT with horizontal and vertical reference lines called the graticule . CRT displays also have controls for focus, intensity, and beam finder. The vertical section controls the amplitude of the displayed signal. This section has a volts-per-division (Volts/Div) selector knob, an AC/DC/Ground selector switch, and

2052-423: The graticule is a sheet of plastic, often with light-diffusing markings and concealed lamps at the edge of the graticule. The lamps had a brightness control. Higher-cost instruments have the graticule marked on the inside face of the CRT, to eliminate parallax errors ; better ones also had adjustable edge illumination with diffusing markings. (Diffusing markings appear bright.) Digital oscilloscopes, however, generate

2109-475: The graticule markings on the display in the same way as the trace. External graticules also protect the glass face of the CRT from accidental impact. Some CRT oscilloscopes with internal graticules have an unmarked tinted sheet plastic light filter to enhance trace contrast; this also serves to protect the faceplate of the CRT. Accuracy and resolution of measurements using a graticule is relatively limited; better instruments sometimes have movable bright markers on

2166-450: The graticule, but also permits offsetting vertically by a limited amount. With direct coupling, adjustment of this control can compensate for a limited DC component of an input. This control is found only on more elaborate oscilloscopes; it offers adjustable sensitivity for external horizontal inputs. It is only active when the instrument is in X-Y mode, i.e. the internal horizontal sweep is turned off. The horizontal position control moves

2223-432: The horizontal speed of the CRT's spot as it creates the trace; this process is commonly referred to as the sweep. In all but the least-costly modern oscilloscopes, the sweep speed is selectable and calibrated in units of time per major graticule division. Quite a wide range of sweep speeds is generally provided, from seconds to as fast as picoseconds (in the fastest) per division. Usually, a continuously-variable control (often

2280-424: The instrument and typically has a resistor of ten times the oscilloscope's input impedance. This results in a 0.1 (‑10×) attenuation factor; this helps to isolate the capacitive load presented by the probe cable from the signal being measured. Some probes have a switch allowing the operator to bypass the resistor when appropriate. Most modern oscilloscopes are lightweight, portable instruments compact enough for

2337-427: The latter setting has significant capacitance (tens of pF) at the probe tip, because the whole cable's capacitance is then directly connected. Most oscilloscopes provide for probe attenuation factors, displaying the effective sensitivity at the probe tip. Historically, some auto-sensing circuitry used indicator lamps behind translucent windows in the panel to illuminate different parts of the sensitivity scale. To do so,

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2394-453: The link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Scope&oldid=1249599178 " Categories : Disambiguation pages Disambiguation pages with surname-holder lists Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages scope Too Many Requests If you report this error to

2451-408: The low-frequency part of the current waveform, right down to DC. The coil still picks up high frequencies. There is a combining network akin to a loudspeaker crossover. This control adjusts CRT focus to obtain the sharpest, most-detailed trace. In practice, focus must be adjusted slightly when observing very different signals, so it must be an external control. The control varies the voltage applied to

2508-454: The lower respiratory tract (pulmonology) Colonoscopy , for examining the large intestine (gastroenterology) Cystoscopy , for examining the bladder (urology) Gastroscopy , for examining the esophagus, stomach and duodenum (gastroenterology) Mediastinoscopy , for examining the anterior mediastinum (cardiothoracics) Laparoscopy , for examining the abdominopelvic cavity (general surgery and gynecology) Nephroscopy , for examining

2565-511: The pelvic and calyceal system of a kidney (urology) Rhinoscopy , for examining the nasal cavity, sinuses and pharynx (otorhinolaryngology) Thoracoscopy , for examining a pleural cavity (cardiothoracics) Ureteroscopy , for examining a ureter (urology) Microscope , a magnifying optical instrument used to see objects that are too small for the naked eye Oscilloscope , a type of electronic test instrument Scope soldering iron , an Australian low-voltage soldering iron Telescope ,

2622-407: The point being observed is not satisfactory, and a probe is generally necessary. General-purpose oscilloscopes usually present an input impedance of 1  megohm in parallel with a small but known capacitance such as 20 picofarads. This allows the use of standard oscilloscope probes. Scopes for use with very high frequencies may have 50 Ω inputs. These must be either connected directly to

2679-417: The probe connectors (modified BNCs) had an extra contact to define the probe's attenuation. (A certain value of resistor, connected to ground, "encodes" the attenuation.) Because probes wear out, and because the auto-sensing circuitry is not compatible between different oscilloscope makes, auto-sensing probe scaling is not foolproof. Likewise, manually setting the probe attenuation is prone to user error. Setting

2736-430: The probe scaling incorrectly is a common error, and throws the reading off by a factor of 10. Special high voltage probes form compensated attenuators with the oscilloscope input. These have a large probe body, and some require partly filling a canister surrounding the series resistor with volatile liquid fluorocarbon to displace air. The oscilloscope end has a box with several waveform-trimming adjustments. For safety,

2793-431: The start event of the sweep. The trigger can be set to automatically restart after each sweep, or can be configured to respond to an internal or external event. The principal controls of this section are the source and coupling selector switches, and an external trigger input (EXT Input) and level adjustment. In addition to the basic instrument, most oscilloscopes are supplied with a probe. The probe connects to any input on

2850-401: The tip further.) There are also current probes, with cores that surround the conductor carrying current to be examined. One type has a hole for the conductor, and requires that the wire be passed through the hole for semi-permanent or permanent mounting. However, other types, used for temporary testing, have a two-part core that can be clamped around a wire. Inside the probe, a coil wound around

2907-404: The trace with the vertical position control. Better oscilloscopes have a polarity selector. Normally, a positive input moves the trace upward; the polarity selector offers an "inverting" option, in which a positive-going signal deflects the trace downward. The vertical position control moves the whole displayed trace up and down. It is used to set the no-input trace exactly on the center line of

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2964-437: The trace. These permit internal circuits to make more refined measurements. Both calibrated vertical sensitivity and calibrated horizontal time are set in 1 – 2 – 5 – 10 steps. This leads, however, to some awkward interpretations of minor divisions. Digital oscilloscopes generate the graticule digitally. The scale, spacing, etc., of the graticule can therefore be varied, and accuracy of readings may be improved. These select

3021-566: The transmission line mismatch at the scope input and the probe causes ringing. The modern scope probe uses lossy low capacitance transmission lines and sophisticated frequency shaping networks to make the 10× probe perform well at several hundred megahertz. Consequently, there are other adjustments for completing the compensation. Probes with 10:1 attenuation are by far the most common; for large signals (and slightly-less capacitive loading), 100:1 probes may be used. There are also probes that contain switches to select 10:1 or direct (1:1) ratios, but

3078-454: The trigger source. It can be an external input, one of the vertical channels of a dual or multiple-trace oscilloscope, or the AC line (mains) frequency. Another switch enables or disables auto trigger mode, or selects single sweep, if provided in the oscilloscope. Either a spring-return switch position or a pushbutton arms single sweeps. A trigger level control varies the voltage required to generate

3135-533: The vertical (primary) input for the instrument. Additionally, this section is typically equipped with the vertical beam position knob. The horizontal section controls the time base or sweep of the instrument. The primary control is the Seconds-per-Division (Sec/Div) selector switch. Also included is a horizontal input for plotting dual X-Y axis signals. The horizontal beam position knob is generally located in this section. The trigger section controls

3192-594: The voltage on the last CRT anode (immediately next to the Y deflection plates). For a circular spot, the final anode must be at the same potential as both of the Y-plates (for a centred spot the Y-plate voltages must be the same). If the anode is made more positive, the spot becomes elliptical in the X-plane as the more negative Y-plates will repel the beam. If the anode is made more negative, the spot becomes elliptical in

3249-463: The waveform of the heartbeat as an electrocardiogram , for instance. Early high-speed visualisations of electrical voltages were made with an electro-mechanical oscillograph , invented by André Blondel in 1893. These gave valuable insights into high speed voltage changes, but had a frequency response in single kHz, and were superseded by the oscilloscope which used a cathode-ray tube (CRT) as its display element. The Braun tube , forerunner of

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