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test-and-measurement:guides:probe-compensation [2024/02/28 00:14] – James Colvin | test-and-measurement:guides:probe-compensation [2024/02/28 22:38] (current) – [Compensating BNC Oscilloscope Probes] James Colvin | ||
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====== Compensating BNC Oscilloscope Probes ====== | ====== Compensating BNC Oscilloscope Probes ====== | ||
- | <WRAP todo> | + | |
- | == Under Construction == | + | {{ test-and-measurement: |
- | </ | + | |
===== Overview ===== | ===== Overview ===== | ||
- | FIXME write an overview, add a picture of some BNC probes | + | BNC oscilloscope |
- | + | ||
- | BNC connectors | + | |
This guide walks through how to make this adjustment for Digilent' | This guide walks through how to make this adjustment for Digilent' | ||
- | |||
---- | ---- | ||
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* A BNC probe to be compensated | * A BNC probe to be compensated | ||
- | * This guide will be using the BNC probes | + | * This guide will use the BNC probes |
* An oscilloscope with a BNC connectors: | * An oscilloscope with a BNC connectors: | ||
- | * Analog Discovery Pro (ADP5250) | + | * [[test-and-measurement: |
- | * Analog Discovery Pro (ADP3450/3250) | + | * [[test-and-measurement: |
- | * Analog Discovery Pro (ADP2230) | + | * [[test-and-measurement: |
- | * Analog Discovery 3 or Analog Discovery 2 with the BNC Adapter | + | * [[test-and-measurement: |
* A square wave source: | * A square wave source: | ||
* Analog Discovery Pro (ADP5250) features dedicated Probe Compensation tabs | * Analog Discovery Pro (ADP5250) features dedicated Probe Compensation tabs | ||
* For other devices, the built-in Arbitrary Waveform Generator can be used to produce 5 kHz square waves | * For other devices, the built-in Arbitrary Waveform Generator can be used to produce 5 kHz square waves | ||
- | * An example WaveForms workspace to compensate a BNC probe on Scope Channel 1 is available for download here. | + | * An example WaveForms workspace to compensate a BNC probe on Scope Channel 1 is available for download |
+ | * A flathead screwdriver to adjust the compensation trimmer on the BNC probe | ||
+ | * A small plastic screwdriver is typically included with BNC probe packs. | ||
---- | ---- | ||
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<columns 100% 50% 50%> | <columns 100% 50% 50%> | ||
Connect the probe that is to be compensated to the desired BNC input channel of the oscilloscope and set the probe to its 10x attenuation setting. | Connect the probe that is to be compensated to the desired BNC input channel of the oscilloscope and set the probe to its 10x attenuation setting. | ||
+ | |||
+ | Note that the BNC probe is connected in such a way to provide easy access to the compensation trimmer. | ||
< | < | ||
- | <figure center|ADXConnectProbe> | + | <figure center|ADP2230ConnectProbe> |
- | {{test-and-measurement: | + | {{test-and-measurement: |
- | < | + | < |
</ | </ | ||
</ | </ | ||
<columns 100% 50% 50%> | <columns 100% 50% 50%> | ||
- | Connect the probe ground clip to one of the outside BNC connectors as that is tied to the system ground, and connect the probe tip to the right angle pin associated with Wavegen Channel 1 − this will be the " | ||
- | |||
If using one of the Analog Discovery Pro 3000 series with no other source of a square wave, attach a BNC minigrabber (or similar) to a Wavegen output and connect the positive end to the probe tip and the ground end to the probe ground clip. | If using one of the Analog Discovery Pro 3000 series with no other source of a square wave, attach a BNC minigrabber (or similar) to a Wavegen output and connect the positive end to the probe tip and the ground end to the probe ground clip. | ||
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< | < | ||
- | <figure center|ADXConnectProbe> | + | <figure center|ADP2230ConnectProbe> |
- | {{test-and-measurement: | + | {{test-and-measurement: |
- | < | + | < |
</ | </ | ||
</ | </ | ||
Line 72: | Line 70: | ||
<columns 100% 50% 50%> | <columns 100% 50% 50%> | ||
- | TEXT | + | Connect the probe that is to be compensated to the desired BNC input channel of the oscilloscope and set the probe to its 10x attenuation setting. |
+ | |||
+ | Note that the BNC probe is connected in such a way to provide easy access to the compensation trimmer. | ||
< | < | ||
- | <figure center|PictureRefName> | + | <figure center|ADP3000ConnectProbe> |
- | {{test-and-measurement: | + | {{test-and-measurement: |
- | < | + | < |
</ | </ | ||
</ | </ | ||
- | |||
<columns 100% 50% 50%> | <columns 100% 50% 50%> | ||
- | Connect | + | If using one of the Analog Discovery Pro 3000 series with no other source of a square wave, attach a BNC minigrabber (or similar) |
- | Connect the probe tip directly | + | <WRAP center round tip 100%> |
+ | It is recommended | ||
+ | </ | ||
- | INFO: The reason you want to connect directly to the source, as opposed to through another probe, is that we want to calibrate the probes with an accurate signal source. Probes themselves, both passive and active, have additional internal circuitry which can distort the square wave, causing the probes to be incorrectly calibrated. | ||
< | < | ||
- | <ADP3450_connectProbe.jpg> | + | <figure center|ADP3000ConnectProbe> |
+ | {{test-and-measurement: | ||
+ | < | ||
+ | </figure> | ||
</ | </ | ||
- | <columns 100% 50% 50%> | ||
- | If using one of the Analog Discovery Pro 3000 series with no other source of a square wave, attach a BNC minigrabber (or similar) to a Wavegen output and connect the positive end to the probe tip and the ground end to the probe ground clip. | ||
- | < | ||
- | < | ||
- | </ | ||
- | |||
- | Open the Scope tool in the WaveForms software. Enable the appropriate channel corresponding to what your probe is attached to (probably channel 1) and set the time division to 200 us/div. | ||
- | |||
- | <columns 100% 50% 50%> | ||
- | If connected to a square wave from a Waveform Generator on a Discovery device, set the time base to 200 us/div and leave the offset and range at their default values. | ||
- | < | ||
- | < | ||
- | </ | ||
- | |||
- | <columns 100% 50% 50%> | ||
- | Then open the Wavegen tool and configure the output to be a 1 kHz Square wave with an amplitude of 1 V. | ||
- | < | ||
- | < | ||
- | </ | ||
- | |||
- | FIXME - use a screwdriver to adjust your probe' | ||
---- | ---- | ||
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--> Analog Discovery Pro 5000 Series (ADP5250) # | --> Analog Discovery Pro 5000 Series (ADP5250) # | ||
<WRAP group> | <WRAP group> | ||
- | |||
- | <columns 100% 50% 50%> | ||
- | TEXT | ||
- | < | ||
- | <figure center|PictureRefName> | ||
- | {{test-and-measurement: | ||
- | < | ||
- | </ | ||
- | </ | ||
- | |||
<columns 100% 50% 50%> | <columns 100% 50% 50%> | ||
Connect the probe that is to be compensated to the desired BNC input channel of the oscilloscope and set the probe to its 10x attenuation setting. | Connect the probe that is to be compensated to the desired BNC input channel of the oscilloscope and set the probe to its 10x attenuation setting. | ||
+ | Note that the BNC probe is connected in such a way to provide easy access to the compensation trimmer. | ||
< | < | ||
- | <ADP5250_connectProbe.png> | + | <figure center|ADP5000ConnectProbe> |
+ | {{test-and-measurement: | ||
+ | < | ||
+ | </figure> | ||
</ | </ | ||
- | |||
- | If connecting to the ADP5250' | ||
<columns 100% 50% 50%> | <columns 100% 50% 50%> | ||
- | < | + | Connect the probe tip to the top tab in the compensation box with the square wave symbol, and the probe ground clip to the lower connector with the ground symbol. |
- | < | + | |
- | < | + | |
- | </ | + | |
- | <columns 100% 50% 50%> | ||
- | Open the Scope tool in the WaveForms software. Enable the appropriate channel corresponding to what your probe is attached to (probably channel 1) and set the time division to 200 us/div. | ||
- | |||
- | Adjust the offset to -1 V and the range to 1 V/div | ||
< | < | ||
- | <AD2APD_ScopeSetup.png> | + | <figure center|ADP5000ConnectProbe> |
+ | {{test-and-measurement: | ||
+ | < | ||
+ | </figure> | ||
</ | </ | ||
- | FIXME - use a screwdriver to adjust your probe' | ||
---- | ---- | ||
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<columns 100% 50% 50%> | <columns 100% 50% 50%> | ||
- | TEXT | + | Connect the probe that is to be compensated to the desired BNC input connector on the BNC Adapter that is associated with the oscilloscope channel you wish to compensate for and set the probe to its 10x attenuation setting. |
+ | |||
+ | Note that the BNC probe is connected in such a way to provide easy access to the compensation trimmer. | ||
< | < | ||
- | <figure center|PictureRefName> | + | <figure center|AD3AD2ConnectProbe> |
- | {{test-and-measurement: | + | {{test-and-measurement: |
- | < | + | < |
</ | </ | ||
</ | </ | ||
<columns 100% 50% 50%> | <columns 100% 50% 50%> | ||
- | Connect the probe to the BNC input of the oscilloscope | + | Connect the probe ground clip to the metal of one of the outside BNC connectors as that is tied to the system ground, |
- | Connect the probe tip directly to the source of the square wave and connect the grounding tip to an associated ground point. | ||
- | |||
- | INFO: The reason you want to connect directly to the source, as opposed to through another probe, is that we want to calibrate the probes with an accurate signal source. Probes themselves, both passive and active, have additional internal circuitry which can distort the square wave, causing the probes to be incorrectly calibrated. | ||
< | < | ||
- | <AD2BNC_connectProbe.jpg> | + | <figure center|AD3AD2ConnectProbe> |
+ | {{test-and-measurement: | ||
+ | < | ||
+ | </figure> | ||
</ | </ | ||
+ | |||
+ | |||
+ | </ | ||
+ | <-- | ||
+ | |||
+ | ---- | ||
+ | |||
+ | |||
+ | |||
+ | ==== WaveForms Setup ==== | ||
+ | A reference workspace with the recommended setup is available for download in the [[# | ||
<columns 100% 50% 50%> | <columns 100% 50% 50%> | ||
- | For the Analog Discovery 3 or Analog Discovery 2, connect | + | Open the Wavegen tool within WaveForms and configure the output on Wavegen Channel 1 to be a 1 kHz Square wave with an amplitude of 5 V. |
+ | |||
+ | Note: If using an ADP 5000 series device, this step is unneeded as you will be using the compensation tabs which automatically provide their own square wave of the appropriate settings. | ||
< | < | ||
- | <AD2BNC_connectSquare image> | + | <figure center|AD3WavegenSetup> |
+ | {{test-and-measurement: | ||
+ | < | ||
+ | </figure> | ||
</ | </ | ||
<columns 100% 50% 50%> | <columns 100% 50% 50%> | ||
- | If connected | + | Open the Scope tool in the WaveForms software. Enable the appropriate channel corresponding |
+ | |||
+ | * Set the level of the rising edge trigger | ||
+ | * Set the Time //Base// to 500 μs/div | ||
+ | * Set the enabled channel voltage //Range// to 1.25 V/div. You can manually type in the box to set this value. | ||
+ | * If not visible, click the gear icon associated with the oscilloscope channel | ||
+ | * Uncheck any additional oscilloscope channels that you are not viewing for visual clarity. | ||
+ | |||
+ | Click the Run All green arrow in the upper right hand corner to start both the Scope and Wavegen instruments. | ||
+ | |||
+ | An example of an unattenuated signal that you might see is shown in {{ref> | ||
< | < | ||
- | <AD2_ScopeSetup.png> | + | <figure center|AD3ScopePrecompensation> |
+ | {{test-and-measurement: | ||
+ | < | ||
+ | </figure> | ||
</ | </ | ||
+ | |||
+ | |||
+ | |||
+ | Use a small flathead screwdriver (a small plastic one is typically included with BNC probes) to adjust your probe' | ||
+ | |||
+ | A small video showing an example of adjusting an overcompensated probe to instead be a flat square wave can be found in {{ref> | ||
<columns 100% 50% 50%> | <columns 100% 50% 50%> | ||
- | Then open the Wavegen tool and configure the output to be a 1 kHz Square wave with an amplitude of 1 V. | + | <figure center|PhysicalAdjustProbeTrimmer> |
+ | {{test-and-measurement: | ||
+ | < | ||
+ | </ | ||
< | < | ||
- | <AD2_WavegenSetup> | + | <figure center|AdjustProbeTrimmerUntilSquare> |
+ | {{test-and-measurement: | ||
+ | < | ||
+ | </figure> | ||
</ | </ | ||
- | FIXME - use a screwdriver to adjust your probe' | ||
- | </ | + | |
- | <-- | + | |
---- | ---- | ||
- | ==== WaveForms Setup ==== | + | ===== Next Steps ===== |
+ | You have now successfully compensated your BNC probe to a particular oscilloscope channel by adjusting its capacitance to match the capacitance of the oscilloscope channel. | ||
- | ===== Next Steps ===== | + | You can find more information about your Mixed-Signal Oscilloscope through its Resource Center, which can be found via the [[test-and-measurement/ |
+ | |||
+ | Other guides you might be interested in include our [[/ | ||
- | FIXME restate what was accomplished | + | All questions, comments, and observations about this and any of our other guides are welcome on the [[https:// |
- | You can find more information about your Mixed-Signal Oscilloscope through its resource center, which can be found via the [[test-and-measurement/ | ||
- | FIXME other call to actions? |