ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Oscilloscope Frequently Asked Questions

Updated on February 24, 2008
TDS3000B Series oscilloscope from Tektronix
TDS3000B Series oscilloscope from Tektronix

Oscilloscope Frequently Asked Questions (FAQ)

What is an oscilloscope?

An oscilloscope is a piece of test an measurement equipment for measuring time varying voltages

Can I measure currents with an oscilloscope?

Yes, there are two ways to measure a current with an oscilloscope.

1. The simplest way is to add a resistor in series with the current you are trying to measure, and then divide the voltage shown on the oscilloscope by the resistance to determine the current.

2. A much more expensive way of measuring current is to use a current probe. Current probes are basically a loop that goes around the wire that has the current you want to measure. They inductivly couple the current signal for measurement for an oscilloscope.

What is a trigger?

On an oscilliscope, the trigger is what tells the scope to start saving data. Usually it is simply a voltage level. When the voltage being measured goes either above or below the trigger level the oscilloscope saves the data before and after the trigger for display on the screen. There are also more complicated triggers, that respond to sequences or glitches, and most digital scopes have an auto trigger feature that will display waveforms with out the measured signal crossing the trigger level.

Why do I see a different frequency output depending on my sampling speed?

If you see a faster frequency on your oscilloscope display when you increase your sampling frequency, it is likely that you were subsampling the waveform. This occurs when you sample something slower than the actual waveform itself. You always need to have your sampling speed at least two times your signal freqency on a digital oscilloscope to get an idea of the frequency of the signal. However, to actually look at the waveform and get meaningful information beyond frequency, you will need to sample faster than this.

Can I use an XX MHz oscilloscope to measure a X Hz signal?

Yes, for most digital oscilloscopes you can reduce your sample speed down to look at signal in the Hertz range.

What is infinite persistance, and how do I use it on my oscilloscope?

Infinite persistance on an oscilloscope just means that it leaves all of the traces of the voltage waveforms on the screen until you decide to to clear it. You can use this feature to see if you have any waveforms that are different than the normal waveform, or in other words, you can look for glitches.

Lecroy WaveJet 300 Series Oscilloscope
Lecroy WaveJet 300 Series Oscilloscope

Any More Quesitons or Comments on Oscilloscopes?

    0 of 8192 characters used
    Post Comment

    • profile image

      eilassej 5 years ago

      hello, i just want to ask, if i am using a current probe on an oscilloscope and get its measurement, is it really the specific amperes (current) that I measure. the physical measurement is in V, i need to make sure that it is also the current that I am measuring.

      say, i measure 400mV using current probe, is it really 400mA? Please advise. thanks.

    • profile image

      kavithareddi 6 years ago

      hi, I need to measure switching speed from oscilloscope, can anybody suggest me?

    • profile image

      mayur 7 years ago

      how do i analyse a frequency spectrum FFT reading for a low-pass filter?

    • profile image

      newtotech 7 years ago

      hi, i was wondering.

      im using an oscilloscope to investigate pulses from ultrafast femtosecond laser.

      first of all, i know the oscilloscope can't cope to measure the femtosecond pulse, however, i was told it can only capture the pulse trains, so my question is, what does the 'period' of the signal indicate..is it the maximum period(duration of the pulse it can cope?) or what? thanks in advance.

    • profile image

      Function Generators 7 years ago

      I like the information give here about the ossilloscope. It can get quiet complicated, with very little information written in basic lay mans language. You have a great selection featured here.

    • profile image

      Mitch Albert 8 years ago

      I have an instrument that has 50 channels that outputs frequencies between 0.5 and 46000 hz. How can I identify the frequency for each channel? According to the manufacturer, it's a secret.

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, hubpages.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: "https://hubpages.com/privacy-policy#gdpr"

    Show Details
    Necessary
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Marketing
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Statistics
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)