Portable Nuclear Gauge Training Center

Official On-Line Training for all Portable Nuclear Density Gauges,
including InstroTek, CPN, Humboldt, Seaman and Troxler Nuclear Gauges.
Accepted Everywhere, Every State

American Portable Nuclear Gauge Association provides a website and association focused on portable nuclear gauge owners and operators. We strive to offer the most in-depth and comprehensive coverage of regulations, issues, references and resources to cover material pertaining to moisture density gauges.

Our Online/Internet Gauge Safety Certification Class fully meets the training requirements to become a gauge operator.  All APNGA classes integrate regulatory and training materials directly from the NRC, Agreement States and U.S. D.O.T., and are the most in-depth and affordable courses on the market today.


Need Help? Click on Our Frequently Asked Questions (FAQs) Below:

When you purchase/enroll in an APNGA course, your enrollment will remain valid for six (6) months.  You will need to complete your course progress and earn your certificate within the 6-month period.

If you have not completed your course within six (6) months of purchasing/enrolling, your course will expire, and all course progress will be deleted.  You will need to purchase a new enrollment to take the course.

Upon completing a course, it is imperative that you download and print your certificate immediately.  Provide a copy to your RSO and retain a copy for your own personal records.  After your course period has expired (6 months), your course progress, course data, test data, and certificate will no longer be accessible.  APNGA is NOT responsible for retaining copies of your certificate. 

If you need a copy of your certificate once it has been removed from our system, you will need to obtain it from your RSO or retake the course and recertify to obtain a new certificate.

APNGA has discontinued selling the Multi-Class (all five classes for 1 user) and the Group Multi-Pack (all five classes for five users) enrollment products.  Of course, we’re still honoring unexpired credit voucher codes for the Multi-Class and Group Multi-Pack enrollments that were previously purchased.  REMEMBER: Codes are only valid for 6-months from the purchase date, so be sure to redeem your unused codes before they expire.

We streamlined the enrollment process by changing the website infrastructure to pre-defined usernames and passcodes with a one-class-per-account arrangement. There is no longer any confusion with “direct” enrollments versus “voucher credit codes”.  Every course purchase provides an assigned Username/Password combination that grants access to a course.

Very few people were using all five courses in the Multi-Class and Group Multi-Pack enrollments.  For example, someone who enrolled in and completed the Gauge Safety Course wouldn’t need to take the HAZMAT Refresher course for three years.  Likewise, someone who needed the Employee Annual Refresher wouldn’t need to take the Gauge Safety Course.  By switching to the one-course-per-account pre-defined username and passcode system, we eliminated the potential issue of overwriting previous enrollments with subsequent enrollments of refresher courses.

Likewise, by pre-defining the account logins and restricting each account to one-course, course data, test results, and certificates are now able to be retained for longer periods of time.  (NOTE: APNGA is NOT responsible for retaining certificates.  As a courtesy and convenience to you, this change in course infrastructure may result in longer retention of certificates.  Use the Certificate Verification Tool at the bottom of the APNGA website to see if a certificate copy remains available.)

When you enroll in an APNGA course, the course enrollment remains valid for 6 months.  Once a course expires, you will need to re-enroll to take the course. 

Here is the duration of each of the five APNGA courses.

  • Gauge Safety Course (with USDOT Hazmat Refresher): Total time: 4 to 6+ hours, comprised of 3+ hours video lessons, plus a 30-question practice test and 30-question certification test and RSO instruction.
  •  Click HERE for Gauge Safety Course Syllabus of topics covered.
  • HAZMAT Refresher Course: 53 minutes, plus a 10-question test.
  • Annual Employee Refresher Course: 1 hour, 45 minutes plus a 10-question test.
  • Radiation Safety Officer (RSO) Course: Total: 6 to 8+ hours.  Training Manual portion 4+ hours, Video portion: 4 hours, 8 minutes.  Click HERE for RSO Course Syllabus of topics covered.
  • Do-It-Yourself (DIY) Annual Audit Course: 41 minutes.

Often times payments get declined because the transaction is for a good or service that is not typical for your account. Payments get coded for each business type by merchant account processors. In the case of our courses, the transaction would be coded as an online software or online education service, which your bank might interpret as potential fraud because it is 1) not the typical type of purchase you make, and 2) it is an online transaction without the card being physically present to swipe or insert into a card chip reader.

Other reasons could be that the name on the transaction does not match the name on the card. Be careful with this, because you if the card belongs to someone else who is purchasing the course for you, THEY need to purchase CREDITS and give you the voucher credit code, and YOU enroll in the course using the code as your payment method. That way, their information does not populate your course completion certificate, and you aren’t enrolled under their account. The instructions on the right-side of the APNGA home page are very specific about this.

Of course, the other reasons for a credit card decline are much more typical.
* The card number could be wrong.
* The card could be expired.
* The CVV code might have been entered incorrectly.
* The card might be maxed out.
* If it’s a debit card, funds may not be available.
* The card could have been reported lost or stolen.
* Etc.

The course videos have a volume control on their control panel.

To adjust the course volume on the video, hover your mouse over the video and the volume control is to the right of the course progress bar.

Also be sure to check your computer’s volume control to ensure it is turned up, so you can hear the course video.

Check your browser.  Be sure you are NOT using Internet Explorer.  Internet Explorer is not compatible.

1. Try using Chrome, FireFox, Edge, or Safari.

2. If that doesn’t work, clear the cookies and cache of your browser to ensure you are working with clean data.

3. If that doesn’t work, try a different computer, or a different device (tablet, iPad, smartphone) to ensure that it is not a browser or network settings issue.

When you complete a course on APNGA, your course completion certificate is downloadable from the website.

METHOD 1: Log into your APNGA account. Look beside your courses. Find your certificate and click on it. Then download it from the browser.

METHOD 2: Go to the bottom of the APNGA Website and click on the Certificate Verification Tool where it says “Verify a Course Certificate”.  Enter the Username of your account.  Your current certificates for completed courses will be listed.  Click on a certificate to download it.

APNGA only stores certificates for CURRENT course enrollment periods. To obtain a copy of your certificate for a class you took in a previous period, you will need to see your RSO. RSOs are required to retain certificates for their operators, inspectors, employees, etc.

AGAIN: Upon completing a course, it is imperative that you download and print your certificate immediately.  Provide a copy to your RSO and retain a copy for your own personal records.  After your course period has expired (6 months), your course progress, course data, test data, and certificate will no longer be accessible.  APNGA is NOT responsible for retaining copies of your certificates. 

If you need a copy of your certificate once it has been removed from our system, you will need to obtain it from your RSO or retake the course and recertify to obtain a new certificate.

To streamline and prioritize support, (especially during COVID-19 contingencies), APNGA provides email tech support.

We also offer LIVE CHAT SUPPORT when an admin is online. Check the bottom of the APNGA ChatBot window to see if the LiveChat icon is showing.  If it is showing, it means that LiveChat may be available.   LiveChat is not guaranteed to be available.  If you enter the LiveChat area and do not receive a response within a few minutes, it’s possible that the admin is logged in but not readily available to chat.

If your chat request is not responded to, many common issues can be answered with the APNGA ChatBot app.  Ask your question in the ChatBot by clicking near the bottom on the words where it says “Send a Message“.  If you find the answer you need, AWESOME!   If you don’t, then send us an email via the Contact Form at the bottom of the web page.  When using the form, provide DETAILS.  We can’t answer blank forms or forms with nothing but the name of a course.  Examples of GOOD and BAD form submissions:

  • Example of Good Form Submission: I can’t log into my APNGA account.  My login email is xyz@email.com.  I’ve clicked “lost password” but didn’t receive a link.
  • Example of Good Form Submission: I’m having trouble redeeming my coupon code.  My code is SAF-3JDLI8D97J-A.  The order number was #82832.  It was ordered by John Doe on February 2, 2021.
  • Example of Good Form Submission: I purchased a username/passcode in the old system.  I tried the conversions to a voucher code as described in the instructions.  It still would not take it.  The username is: APNGA39394.  The passcode is: 3KF8DN.  It was ordered on August 5, 2020.
  • Example of Good Form Submission: My certificate was printed with John Doe’s name on it.  My name is Joe Smith.  My course order number was #81544.  Jane Jones enrolled me in the course using voucher code HAZ-DK86DKDNW-A on March 2, 2021.
  • Example of Bad Form Submission: Gauge Safety Course.
  • Example of Bad Form Submission: I can’t login.
  • Example of Bad Form Submission: Call me at 717-555-1212.
  • Example of Bad Form Submission: Need my certificate.

When we receive Contact Forms or emails that contain no information and no details, we really can’t do anything with them.  We have to prioritize our time to work with people who provide us enough information where we can look into the order details, user accounts, coupon code settings, etc.  It sometimes requires a little bit of “detective work” to figure things out.  We cross-reference orders, to people, to voucher codes, to email addresses, etc.  Sometimes we find it’s a spelling error in the name or the email address.  Sometimes we find that someone mixed up their voucher code, or perhaps used a letter “O” instead of the number “0”.  Sometimes we find that accounts were co-mingled due to not following instructions, and we need the details to sort it out.  So, in advance, we’re asking you to “Help us help you.”  Give us something to work with.  We need details.

Use the online forms or send an email to support@apnga.com, and we will get to your specific issue as soon as possible. Most issues require a bit of research to cross-reference order numbers, usernames, email addresses, and voucher code numbers, etc… so putting people “on hold” while we dig into the details is not a good use of anyone’s time.

We do not offer telephone tech support.  Why?  Because it slows down the “detective work” process in getting your issue resolved.  And while we’re on the phone with one customer, other customers end up leaving voicemail messages like the “Bad Examples” above, without providing details, and they often don’t leave their email address or spell their names, so we aren’t able to provide good service to them.  There are a lot of reasons.  Just realize, we want to resolve every tech support issue as quickly and efficiently as possible.  With our email support system, our average time to resolve an technical support issue is between 4-6 minutes, compared to 10-15 minute phone calls that keep you waiting on-hold.

As we discover trends and streamline resolutions, we update our APNGA ChatBot with new FAQs and response data, so it becomes more useful over time.  It uses artificial intelligence to match your questions with answers in our database…  so it continually gets “smarter” and delivers more meaningful answers.

We typically answer every support email within 4 to 6 hours.  Almost every support ticket is resolved same-day.  With over 66,000 past and present customer accounts to keep up with, we’d like to think same-day resolution is a decent track record.

Optimize Your Productivity and Cost Effectiveness!

The accessibility and flexibility of our Internet classes allows the viewer to spend as much time as needed to fully prepare for and comprehend the required Gauge Safety and U.S. D.O.T. classes and tests.

Companies keep their employees in-house and on the job, saving significant money on travel and training costs.


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Click the blue “Buy Classes” button below and purchase login credentials for one or more courses.  Or click on a specific course at the top of this page.

You will purchase the LOGIN CREDENTIALS for yourself or others.

For each course you purchase, you will be emailed a USERNAME and PASSWORD combination via email.  The person attending a class will log in with the username and password combination to take that class.

If you are purchasing for YOURSELF, log in with the username and password you purchased for your course(s).   If you are purchasing for your employee(s), provide them with the usernames and passwords you purchased for them to log in and take the course(s).

(Take a Class I’m Already Enrolled In)

Click the Course Login button below.  You will be asked what your login credentials look like.  Select the option that most closely looks like yours.  (To log into your course, you must have a username and password from purchasing the course and/or redeeming a credit voucher code.)


In the new login system, there is only ONE class per login account.  Your username and password combination are PRESET, and cannot be changed.  Do not lose your username and password.  If you are enrolled in two different courses, you will have a SEPARATE login (username and password) for each of them.

Courses are valid for six (6) months from the date of enrollment.  Each enrollment ends at the end of six months.  Once a course expires, course data, test results, and certificates will no longer be accessible.  Therefore, be absolutely sure to complete your course and print your certificate prior to your course expiration.