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Application Notes for Function Generators, Oscilloscopes, Device Programmers, Digital Multimeters, Test Instruments
(Lab and Test Equipment)
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EPROM Programmer
(Industrial Computers and Embedded Computer Components)
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Function Generators
(Lab and Test Equipment)
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Function Generators: Achieving Low Level Output
(Lab and Test Equipment)
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From this Article:
The minimum output level of BK function generators is approximately 180 millivolts peak-to-peak or 3.5 millivolts rms when terminated into 50 ohms. Some applications such as injecting an input signal into a radio receiver or other sensitive amplifier...
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Function Generators: AM Receiver Alignment
(Lab and Test Equipment)
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From this Article:
2.If a precise center frequency counter should be used during set up. Function generators with built in frequency counters (digital display) simplify this step. Before sweep operation begins, set the frequency dial on the generator to obtain the...
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Function Generators: Amplifier Overload Characteristics
(Lab and Test Equipment)
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From this Article:
The overload point for some amplifiers is difficult to determine using a sine wave input. The triangle waveform is ideal for this type of test because any departure from absolute linearity is readily detectable. Using the triangle output, the peak...
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Function Generators: Amplifier Performance Evaluation Using Square Waves
(Lab and Test Equipment)
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Function Generators: Amplitude Modulation
(Lab and Test Equipment)
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From this Article:
Amplitude modulation, or AM, is the varying of the amplitude of one signal in accordance with the amplitude of another, lower-frequency, signal. Many function generators allow the user to amplitude-modulate the main output via either an external or...
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Function Generators: Digital Frequency Selection
(Lab and Test Equipment)
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From this Article:
Frequencies can be switched electronically by using the set up shown in Fig. 19. The preset voltages can be digitally selected and applied to the VCF input jack on the generator. Although provisions for two frequencies are shown, additional...
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Function Generators: FM Communications Receiver Alignment
(Lab and Test Equipment)
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From this Article:
The test set up of Fig. 17 can be used for alignment of FM communications receiver IF’s and discriminators using the 455 kHz IF frequency. For accurate frequency adjustments, a 455 kHz crystal-controlled marker source should be used.
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Function Generators: Frequency Response Measurements, Linear / Log Display - Introduction
(Lab and Test Equipment)
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From this Article:
Most sweep generators are equipped with logarithmic and linear sweep capability. Logarithmic frequency response curves are quite common on specification sheets for amplifiers and other equipment. Whereas linear characteristics give more resolution of...
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Function Generators: Frequency Response Measurements, Linear / Log Display - Procedure
(Lab and Test Equipment)
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From this Article:
1. Connect the GCV output of the generator to a vertical input of the oscilloscope, as shown in the figure. Though not used for horizontal deflection, the GCV output is useful in setting and determining frequency points on the display.
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Function Generators: Frequency Response Measurements, Linear Display - Frequency Response Display
(Lab and Test Equipment)
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From this Article:
When using a conventional oscilloscope probe, the display will be an envelope such as shown in Fig. 10. The relative gain or attenuation of all frequencies within the swept band is displayed. The display may be analyzed for acceptable or unacceptable...
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Function Generators: Frequency Response Measurements, Linear Display - Introduction
(Lab and Test Equipment)
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From this Article:
Function generators with sweep capability are ideal for checking the frequency response of such devices as amplifiers, bass and treble controls, band pass filters, low or high pass filters, coupling networks, speakers and speaker enclosures. IF...
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Function Generators: Frequency Response Measurements, Linear Display - Test Set-up
(Lab and Test Equipment)
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From this Article:
With the generator’s sweep turned off, vary the basic operating frequency of the unit. The GCV output will cause the dot on the scope screen to deviate from left to right. Direction of the deviation depends on the particular generator. Some move to...
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Function Generators: Frequency Response Measurements, Linear Display - Tone Control Test
(Lab and Test Equipment)
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From this Article:
If an audio amplifier under test is equipped with bass and treble controls, the effects of these controls on overall response can be determined by running frequency response tests while adjusting the controls throughout the range of adjustment. Fig.
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Function Generators: Frequency Response Measurements, Linear/Log Display - Introduction
(Lab and Test Equipment)
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From this Article:
Most sweep generators are equipped with logarithmic and linear sweep capability. Logarithmic frequency response curves are quite common on specification sheets for amplifiers and other equipment. Whereas linear characteristics give more resolution of...
( View Full Article)
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Function Generators: Frequency Response Measurements, Linear/Log Display - Procedure
(Lab and Test Equipment)
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From this Article:
1. Connect the GCV output of the generator to a vertical input of the oscilloscope, as shown in the figure. Though not used for horizontal deflection, the GCV output is useful in setting and determining frequency points on the display.
( View Full Article)
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Function Generators: Frequency Response Using a Digital-Storage Oscilloscope
(Lab and Test Equipment)
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From this Article:
The advent of digital storage oscilloscopes or DSO’s facilitates the frequency response measurements discussed in the last section. With a conventional scope, the generator’s sweep rate must be kept fast enough to avoid flicker, but slow enough to...
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Function Generators: Frequency Response...Linear Display - Frequency Response Display
(Lab and Test Equipment)
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From this Article:
When using a conventional oscilloscope probe, the display will be an envelope such as shown in Fig. 10. The relative gain or attenuation of all frequencies within the swept band is displayed. The display may be analyzed for acceptable or unacceptable...
( View Full Article)
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Function Generators: Introduction
(Lab and Test Equipment)
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From this Article:
Because of the wide range of function generators currently available, and the wide array of features which they offer, the inventive user can undoubtedly devise many more applications than can be covered here. Therefore, this section endeavors to...
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Function Generators: Preset Frequency Selection
(Lab and Test Equipment)
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From this Article:
In test and design work where several frequencies are to be used repeatedly, it is convenient to be able to pre-select these frequencies with a minimum of effort. As shown in Fig. 18, the VCF feature of many function generators can be used together...
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Function Generators: Testing Digital Logic Circuits
(Lab and Test Equipment)
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From this Article:
9. Modern function generators are well suited for testing digital logic circuits. They can supply square waves, pulses, or gated pulse trains. On many generators, these waveforms can be swept in frequency if desired. Using variable symmetry, narrow...
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Function Generators: Testing Modulation Limiters and Compression Amplifiers
(Lab and Test Equipment)
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From this Article:
Compression amplifiers are often used in communications equipment to provide better audibility over a wide range of input conditions. One very common application is modulation limiting in CB radio transmitters. Attack time, the time delay from...
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Function Generators: Testing Speakers and Impedance Networks
(Lab and Test Equipment)
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From this Article:
A function generator can be used to provide information regarding the input impedance of a speaker or any other impedance network vs. frequency. In addition, the resonant frequency of the network can be determined.
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Function Generators: Testing Tone Burst Decoders
(Lab and Test Equipment)
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From this Article:
A tone burst decoder requires a specific tone frequency such as 2250 Hz for a specific minimum period of time (120 milliseconds) before it will provide an output. This delay prevents voice signals or other random on-frequency signals from falsely...
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Function Generators: Troubleshooting by Signal Substitution
(Lab and Test Equipment)
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From this Article:
A variation on the signal tracing technique is to inject an audio signal at various points in the circuit under test, to substitute for the normal signal. In this technique, the signal is first injected nearest the speaker and is moved toward the...
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Function Generators: Troubleshooting by Signal Tracing
(Lab and Test Equipment)
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From this Article:
One of the most common methods of troubleshooting defective audio equipment is to inject a signal from a function generator at the input of the device under test. An oscilloscope is then used to check the output at each stage, starting nearest the...
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Function Generators: Using a Function Generator as a Bias and Signal Source
(Lab and Test Equipment)
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From this Article:
Most modern function generators are able to superimpose a DC offset voltage on their AC signal output. As shown in Fig. 7, this capability can be used to bias a transistor amplifier under test as well as furnish the AC component of the input signal.
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Guidelines for the Sensible Use of a Digital Multimeter
(Multimeters and Electrical Test Meters)
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From this Article:
Make sure the battery is good. Always replace battery immediately when a meter's low battery indicator is displayed. A low battery may cause inaccurate readings and may cause potential safety concern.
( View Full Article)
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Oscilloscopes: Add Mode Applications
(Lab and Test Equipment)
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From this Article:
The oscilloscope’s “add” mode can be conveniently used to measure a signal with a reference point other than earth ground. For example, if you wanted to measure the signal present across R2 in Fig. 24, you would use the following technique:...
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Oscilloscopes: Amplitude
(Lab and Test Equipment)
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From this Article:
A standard NTSC composite video signal is 1 volt peak-to-peak, from the tip of a sync pulse to 100% white. This 1 volt peak-to-peak signal is divided into 140 equal parts called IEEE units. The zero reference level for this signal is the blanking...
( View Full Article)
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Oscilloscopes: Catching Rapid One-time Events
(Lab and Test Equipment)
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From this Article:
Figs. 48a through 48c represent captures of quickly-occurring one-time events that would be difficult to observe on a standard oscilloscope due to their rapid and one-time nature.
( View Full Article)
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Oscilloscopes: Catching Slow Events Using Roll Mode
(Lab and Test Equipment)
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From this Article:
On a conventional oscilloscope, slow events, even though they may be repetitive, pose a particular problem when timing measurements are required. This is because the waveform is often only a dot moving slowly across the screen, rather than a line.
( View Full Article)
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Oscilloscopes: Color
(Lab and Test Equipment)
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Oscilloscopes: DC Voltage Measurements
(Lab and Test Equipment)
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From this Article:
This technique is used to measure the level of a simple dc voltage where no waveform is present. This would result, for example, from connecting the scope directly to the output of a dc power supply. The example uses +5 volts dc, which is a common...
( View Full Article)
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Oscilloscopes: Elimination of an Undesired Signal Component
(Lab and Test Equipment)
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From this Article:
Another application of the add mode is to cancel out the effect of an undesired signal component which is superimposed on the signal you wish to observe (for example, undesired 60Hz hum superimposed on an rf signal). The first waveform of Fig. 26...
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Oscilloscopes: Frequency Measurements
(Lab and Test Equipment)
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From this Article:
Frequency measurements are made by measuring the time period of one cycle of a waveform and calculating the frequency, which equals the reciprocal of the time period.
( View Full Article)
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Oscilloscopes: Frequency Response Measurements
(Lab and Test Equipment)
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From this Article:
A sweep generator and the X-Y mode of the oscilloscope maybe used to measure the audio or rf frequency response of an active or passive device, such as an amplifier, band pass filter, coupling network, etc.
( View Full Article)
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Oscilloscopes: History
(Lab and Test Equipment)
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From this Article:
In 1953, the NTSC (National Television Systems Committee) established the color television standards now in use by the television broadcast industry in the United States and many other countries. It was, of course, compatible with the monochrome...
( View Full Article)
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Oscilloscopes: Horizontal Sync
(Lab and Test Equipment)
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From this Article:
The “beginning” of a line of horizontal scan occurs at the leading edge of the horizontal blanking pedestal. In a television receiver, the horizontal blanking pedestal starts as the electron beam of the CRT reaches the extreme right-hand edge of the...
( View Full Article)
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Oscilloscopes: Instantaneous DC Voltage Measurements
(Lab and Test Equipment)
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From this Article:
This technique may be used to measure an instantaneous dc level at some point on a waveform, such as that in Fig. 22. Though this measurement can be performed on either scope channel, this example uses channel 1.
( View Full Article)
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Oscilloscopes: Measurement of a Simple DC Voltage
(Lab and Test Equipment)
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From this Article:
This technique is used to measure the level of a simple dc voltage where no waveform is present. This would result, for example, from connecting the scope directly to the output of a dc power supply. The example uses +5 volts dc, which is a common...
( View Full Article)
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Oscilloscopes: Observing Video Signals Using Delayed Sweep
(Lab and Test Equipment)
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From this Article:
TV triggering allows you to select either vertical or horizontal sync pulses so that a stable video waveform may be observed on the oscilloscope display. When TV triggering is used in conjunction with delayed sweep (not all oscilloscopes have the...
( View Full Article)
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Oscilloscopes: Peak-to-peak Voltage Measurements
(Lab and Test Equipment)
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From this Article:
1. Connect the signal to be measured to the input connector, set the oscilloscope to display the channel that you wish to use, and set the input coupling switch to the AC position. Set the Volts/Div and Time/Div controls to obtain a normal display of...
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Oscilloscopes: Percentage of Modulation Measurements
(Lab and Test Equipment)
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From this Article:
3. Adjust the Volts/Div and variable input attenuator controls so that several divisions of vertical amplitude are displayed. Since this measurement simply calls for a ratio, it is not necessary to be concerned with the scale factor (Volts/Div).
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Oscilloscopes: Phase Difference Measurements
(Lab and Test Equipment)
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From this Article:
2. Select the signal which is leading in phase as the trigger source and use the Volts/Div and variable input attenuator controls to adjust the two waveforms so they are equal in amplitude.
( View Full Article)
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Oscilloscopes: Pulse Jitter Measurements
(Lab and Test Equipment)
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From this Article:
1. Apply the signal to one of the input jacks and set the oscilloscope to display the channel to be used. Use the Volts/Div control to adjust the waveform so that it is easy to observe. Special care should be taken to adjust the trigger controls for...
( View Full Article)
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Oscilloscopes: Pulse Rise Time and Fall Time Measurements
(Lab and Test Equipment)
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From this Article:
1. Apply a signal to the input jack and set the oscilloscope to display the channel to be used. Use the Volts/Div control, the variable input attenuator control, and the vertical position control to adjust and position the waveform on the 0% and 100%...
( View Full Article)
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Oscilloscopes: Pulse Width Measurements
(Lab and Test Equipment)
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From this Article:
2. Use the Volts/Div and Time/Div controls to adjust the display so the waveform is easily observed. Use the vertical position control to position the pulse over the center horizontal graduation line. Use the horizontal position control to align the...
( View Full Article)
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Oscilloscopes: Push-pull Amplifier Measurements
(Lab and Test Equipment)
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From this Article:
Because the two outputs of a push-pull amplifier are out of phase, they tend to subtract. It is necessary to invert one channel to cause the signals to add.
( View Full Article)
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Oscilloscopes: Relative Measurements
(Lab and Test Equipment)
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From this Article:
If the amplitude and period of some reference signal are known, an unknown signal may be measured for amplitude and period without the variable input attenuator and variable time base controls set to the calibrated position. The measurement is made...
( View Full Article)
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Oscilloscopes: Time Difference Measurements
(Lab and Test Equipment)
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From this Article:
1. Apply the two signals to the oscilloscope’s input jacks and select the dual-trace display mode (either the chop or alternate display mode). Chop is usually chosen for low-frequency signals and alternate for high-frequency signals.
( View Full Article)
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Oscilloscopes: Time Measurements
(Lab and Test Equipment)
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Oscilloscopes: Using Square Waves to Test Amplifiers
(Lab and Test Equipment)
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Oscilloscopes: Vertical Sync
(Lab and Test Equipment)
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Oscilloscopes: Waveform Magnification Using Delayed Sweep
(Lab and Test Equipment)
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Oscilloscopes: X-Y Mode Applications - Phase Measurements
(Lab and Test Equipment)
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Oscilloscopes: X-Y Mode Applications Phase Measurements
(Lab and Test Equipment)
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Test Instrument Safety
(Multimeters and Electrical Test Meters)
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From this Article:
Normal use of test equipment exposes you to a certain amount of danger from electrical shock because testing must often be performed where exposed voltage is present. An electrical shock causing 10 milliamps of current to pass through the heart will...
( View Full Article)
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