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I need help in deciding what kits to sign up for - what kind of help can I get?

Let us help you develop a plan based on your scope and your needs. NAPT staff develops hundreds of plans each year for our members. Let us work on your plan next.

Why is NAPT nonprofit?

Simple answer: NAPT could not provide the services it does to the metrology community without it being nonprofit.  Only because of the numerous sponsors, the donation of the kits, the volunteering of the technical advisors that assist in the design of the schemes and the one-on-one help given to members are we successful.  All this could only happen in a nonprofit environment. In short, NAPT exists because of the metrology community supporting the services NAPT provides back to the metrology community.

What’s the difference between a proficiency test (PT) and an interlaboratory comparison ( ILC)?

An Interlaboratory Comparison (ILC) looks at measurement results between several laboratories. The purpose of an ILC could be to evaluate methods, different standards, environmental effects, competency of staff or the lab, or other factors in the measurement process. A proficiency test (PT) is designed to evaluate competency or proficiency, and is a type of ILC.

Does NAPT follow PT plans created in the Customer Portal?

While you can create a detailed plan in your NAPT customer portal, it is the responsibility of the participant to notify us which kits they want to actually enroll in.

How many kits can I sign up for at once?

The web site was designed to allow participants to enroll in three kits at once, which is the most common number.  Please contact NAPT directly when requesting more than 3 kits so we can apply all discounts you are entitled to for multiple enrollments.

Why should I use NAPT vs. other proficiency testing providers?

When you compare NAPT against other metrology PT providers, you will find there really is no comparison. Compare NAPT’s full time staff to other PT providers who conduct PTs as a side job.  Compare the ability to get technical advice from 50 plus metrology experts, quality of expertise, and the best customer portal of any PT provider. Further, your data submittal will be compared to 100 other like organizations. AT NAPT, we love to say to new participants “We Dare You to Compare NAPT vs them” and you too will see there is no comparison!

You don’t offer a kit that I need - what are my options?

We can acquire an artifact and design a kit to meet your needs, we can work with you on conducting your own intras ILC/PT and/or you can use the exact same application we use and conduct your own intra laboratory comparisons.

I need more information about QMS Navigator. Where can I get it?

Try out our online demo, consult with our technical staff who designed the app, or with our lead programmer – set up a personal web meeting by contacting NAPT staff and let them know your preference.

Can you tell me who else participated in this proficiency test?

No, we cannot. The participants are anonymous and may not be disclosed by NAPT. Please do not reach out to other labs you may know that are enrolled as that would be a violation of your enrollment.

What types of kits do you have?

NAPT services the metrology and test community and most of the kits offered are based on the needs of those participants. Our list of kits, including the disciplines are listed on the NAPT website. Please visit the website and use the user friendly sort tool to find the kit you need, or feel free to contact NAPT directly and we will help you find the kit that best fits your needs.

Why doesn’t NAPT have their Accrediting Body's symbol on their reports?

NAPT has participants who are accredited by all the accrediting bodies and because of that, NAPT has a long-standing policy that we do not advertise for any one accreditation body - we like them all.  Also, NAPT is accredited to ISO 17043 so all of NAPT reports are recognized and accepted by all accreditation bodies.

Does NAPT ship its kits outside of North America?

No. NAPT does not ship outside North America. As an alternative, you may want to consider using the QMS Navigator as a helpful tool for your proficiency testing needs.

What are NAPT’s hours of operation?

NAPT staff is available from 8:00 a.m.-5:00 p.m. Central Standard Time.

I haven’t received my kit and I have my audit coming up. Can you help?

Yes, NAPT can provide you with a letter noting that you are signed up for a kit and the expected date you will be receiving the kit.

My lab is outside of the USA - why do I have to pay for the importing and exporting of a kit?

Shipping kits to labs outside of the continental USA comes with additional costs. Because of these additional costs, all international participants are required to pay their share of importing, exporting, taxes, and fees that come with shipping a kit. NAPT tries its best to alleviate costs by scheduling international kits together.  

Does NAPT calculate uncertainties for participants?

No. It is the responsibility of the lab submitting results to calculate all uncertainties associated with any measurement made by them. It is not NAPT’s place to state whether or not a reported uncertainty is correct or not. That oversight should come from your management and ultimately the accrediting body who granted your accreditation.  

What is a normalized Error (En)?

A normalized error compares a lab’s measurement result and its associated uncertainty with a reference value and uncertainty to determine if they are in agreement. If the absolute value of En is greater than one, the two measurements are not in agreement. For more information on calculation of En, see ISO/IEC 17043:2010 Conformity Assessment-General Requirements for Proficiency Testing.

Can I talk with someone about an unsatisfactory measured value?

Yes, please send a detailed email to and we will get you in contact with the proper technical advisor or NAPT’s technical manager who will be able to assist.

How do you want me to calibrate your artifact?

The main goal of any enrollment is to compare measurements using your processes and reference values and evaluate your results against other like organizations.

Why did I fail a set point?

There could be a number of reasons why your performance was unsatisfactory.  NAPT staff cannot tell you why without having greater knowledge of your measurement process.  NAPT members have the ability to work directly with the 50+ technical advisors NAPT currently has assisting its members.  If you wish to receive assistance from a technical expert, contact NAPT and we will start that process with you.

Why are my En calculations different from the values on your reports?

The Evalue can be different because the values used by you are not the values used by NAPT. Numbers found on the preliminary or final report are not the exact values NAPT uses. These numbers are rounded. The only way that you are going to guarantee that your Ecalculations matches NAPT calculations is to use the exact same numbers. Feel free to contact NAPT for the exact numbers used in any calculation.

Why aren’t the En values on the preliminary report?

The primary purpose of the preliminary report is to ensure NAPT has entered your data submittal correctly into the QMS Navigator Management Application.  To issue a preliminary report with values that may change would be inappropriate and misleading.

Do you have someone I can speak to about my data results?

Yes, please send an email to and NAPT staff will coordinate with the appropriate technical advisor to set up a date and time to discuss your results.

What happens if I do not put the NAPT kit in a protective outer box?

You will be invoiced for an administrative fee to address your shortcoming.  This may include damages that occur while in-transit.

I got my kit start notice but haven't received the kit yet. When will I get it?

In accordance with the start notification, you should receive the kit in approximately 2 weeks. If you don’t receive it after the 2 weeks, contact NAPT staff.

I signed up for a kit and haven't been given an approximate date to receive the kit. When will I be scheduled?

Upon your reply to the acceptance notice. If you have not received an acceptance notice for the kit please contact NAPT for assistance.

Do I have to wait 10 days before receiving a final report?

No, as long as the block is in a what is referred to as “Issue Final Reports” status, participants are welcome to waive the 10 day waiting period.

Why have I not received any kits yet?

There may be multiple reasons why you have not received a kit in the timeframe you expected. Please contact us and let’s ensure you are signed up for the kit you are waiting for and that you have responded to the acceptance notification email. It’s also possible other labs may have extended their participation time and NAPT staff has had to adjust the schedule based on unforeseen circumstances.

I received my preliminary report but I need my final report now – how can I get it?

Participants who are in good standing and enrolled in a block where a technical review has been performed may waive the 10-day grace period. Then the report will be available in your customer portal and you should receive an email from NAPT stating your final report is available in your customer portal.

Where do I send my data?

The preferred method is to submit data via your customer portal. If you wish, you can also email your data submittal to directly to a staff member, fax it to NAPT or send it via U.S. mail.

Can I retake a test?

Yes, if you require a retest, please contact to discuss your options for taking a retest.

Why hasn't my report been sent?

There are a number of possible reasons that a report hasn’t been issued. It’s possible the block is under technical review, the enrollment fees haven’t been paid, the data hasn’t been submitted, or the original submittal has issues and NAPT is waiting for a response. Please contact us and we’ll help you find out the status of your enrollment.

How many of my technicians can take part in the test?

For each enrollment, one set of data is standard; however, quite a few organizations submit data for each technician qualified to make that type of measurement. If you would like to add additional technicians, please contact NAPT. There is a small fee to add technicians to current enrollments.   

Can I hand-deliver the kit?

Yes. There is an option on the Shipping and Receiving form. Please mark the form accordingly and send the form back to NAPT. 

How do I submit my revised data?

All revised data can be submitted via your customer portal or directly to Please note that when submitting revised data, you must provide objective evidence supporting your request for change which must be approved before any submittal will be revised.

Why don’t I see the kits I signed up for in the Customer Portal?

If your kit is not in the customer portal, chances are it was not fully processed. Please contact NAPT to check the details for your request.

I tried signing up on your website, but I do not think it worked - can you help me?

Of course, please give us a call, NAPT staff is here to help. If you wish you can also fill out the online  form or send an email to us at

Why can’t I see my data on the Customer Portal?

There could be several reasons:  You didn’t send back your receiving form.  The enrollment fee hasn’t been paid. You aren’t looking in the right place - check under “review results”.  We may not have your correct email - check the NAPT customer portal.  Pending access to the customer portal is very dependent on having a valid working email address and password . Please contact NAPT staff and they will help you get into your customer portal.

What is the intra-laboratory PT process?

An intra is an in-house proficiency test (custom proficiency test for your location). The process includes filling out the NAPT request to develop an INTRA and submitting additional supporting documentation. NAPT will review your information, issue an invoice for the development, review and reporting.  NAPT will then create a unique intra based on your internal needs.  An instruction sheet (IS), Data Reporting Sheet (DRS) and other related documents will be sent to you for editing and approval.  After your organization acquires measurements, data submittals will be shared with staff, then processed per NAPT’s statistical procedures. Please note that a minimum of three data submissions are required.

I finished making measurements - where do I send the kit next?

Upon receipt of the data reporting sheet (your data submittal), NAPT staff will email the primary contact a ship-to notification indicating where the kit will be shipped to next.

How many days can I have the kit for?

All participants are allowed to have the kit on site for 3 days. If a participant needs additional time, they will need to contact NAPT staff and arrange ahead of time to avoid late fees.  Staff will try to accommodate special requests. If no prior arrangement is made, a late fee will be assessed.

I found damage to the kit - what is the protocol for reporting it?

Contact NAPT Staff ASAP with a phone call or an email to start the process. Our email address is  We will need details along with photos of the damage. NAPT staff will work with you on what happens next, whether it be sending the kit to one of our pivots labs or back to NAPT for additional evaluation, NAPT will assess the details and make a determination on how best to proceed.

What is the lead time of a kit?

Some kits are scheduled months out, others three to four weeks. It’s best to contact staff via a quick call or send an email to with your need and staff will get back with you ASAP.   

I just signed up for a kit - how long before I receive the kit?

This varies depending on the kit you selected. On average, a participant will receive a kit within two to four weeks.  Members can request start dates and in extreme cases a kit can be scheduled to help a member meet a specific need. 

I need to pay for my enrollment fees with a credit card - who should I contact?

Please call the main number, (952) 303-6126 and you will be directed to the accounting person who will assist you with that transaction.

I have a purchase order - why can’t a report be issued?

A purchase order is not proof of payment.  It is NAPT policy not to issue any report unless enrollment fees have been received. NAPT accepts enrollment fees via credit card , electronic transfer or by a check issued to NAPT.

Can I pay for my enrollment fees on your website?

Currently, NAPT does not offer the capability to pay for enrollment fees via the website.  That option will be available soon. In the interim we ask that you contact NAPT directly and we will handle that transaction by phone.

I want to use a credit card to pay for my enrollment fees - how much is the convenience fee?

The convenience fee is a percentage based on the total cost of the invoice and varies by card.  Contact us to determine exact fees ahead of time. 

Can I pay using ACH?

Yes. NAPT accepts ACH transactions and EFT. Please call NAPT for a W9 to set us up in your accounting system.

How quickly can I receive an artifact?

The average wait for an ILC/PT is 2 to 4 weeks; although, there are several ILC/PTs that are scheduled out 2 to 4 months.  Please contact NAPT for ILC/PT availabilities.

Useful Link

Can you forward my reports to my AB?

No, NAPT maintains confidentiality of reports at all times. Participants are responsible for sharing their PT results with their accrediting body.

Will my accreditation body accept reports issued by NAPT?

As an accredited Proficiency Testing provider, NAPT reports are recognized and accepted by all the leading accreditation bodies.

What are reference values?

The reference value is a value against which your results are compared. In any proficiency test, the results are only as good as the established values assigned.

NAPT's process for establishing the reference value was designed with the help of lead statisticians in the metrology community plus technical oversight by statisticians at NIST. Using standard technical practices, an analysis is performed and an appropriate reference value is assigned to the data set. We ensure that reference values and their associated uncertainties assigned are stable and worthy of comparison.

Pivot and reference labs are accredited, helping to ensure credibility of reference values. To further analyze the results we also perform the following statistical reviews: Two Sigma, Three Sigma, Chauvnet Criterion, Sample Median, Trimmed Mean, Interquartile, Q-Test, and Thompson Technique. This is done in all cases to assure sound and meaningful results are published. During the course of each proficiency test, comprehensive technical reviews are conducted before, during, and after a kit is put into distribution. This is done to assure test integrity, establish and/or validate reference data and check for trends and/or anomalies in the data. Our technical advisors believe our technical review is unmatched by any ILC Provider.

These requirements are described in NAPT Quality Procedure 407-1 Data and Statistical Analysis Procedure. Only after a careful review of the data does NAPT assign an established reference value. To prematurely assign a reference value could be inaccurate and may result in a value that would not pass a robust analysis. Doing so would not ensure confidence in the reference value assigned. Making an assumption that a single measurement is the correct measurement, is not a technically sound process for ensuring the validity of the data. (No single laboratory is infallible.) That is why only after a thorough review of all data, should a reference value be assigned.

Do your technical advisors have access to my results?

No, the technical advisors assigned to a proficiency test do not have access to client data. The technical advisors are given raw data only. We know that one of the most important factors in designing meaningful proficiency tests is the involvement of technical advisors. One of the strengths behind NAPT’s success is the technical experts that assist us on a daily basis. The technical advisor is an expert in the field for which they provide assistance.

Is NAPT accredited?

NAPT is an ISO/IEC 17043 accredited provider. NAPT Is the only proficiency test provider that can meet all of your needs via our offerings of proficiency tests. You can review our scope of accreditation on this site.

We are very proud of our accreditation, but we believe there is more to being a first-class proficiency testing provider than just being accredited.  Our level of service, number and variety of tests offered, and quality of value added proficiency tests are just a few examples of why NAPT is the clear choice when selecting a PT provider. We would ask you to compare the services that NAPT offers against other providers and after comparing everything we have to offer, you will see there really is no comparison.

What are the benefits of Membership?

Members receive:

  • ILC/PT Membership Discounts 
  • Automatic enrollment in NAPT’s Rewards Program to earn points towards free ILC/PT participations
  • Access to Technical Expertise of our Technical Director & technical expertise of NAPT's vast cadre of Technical Advisors
  • Listing on NAPT’s Website with a link to your website
  • Annual Membership Certificates showing your support of NAPT

What are the costs to participate?

NAPT's Fee Schedule is posted under Services.   NAPT believes you deserve real value for your participation and it is important to choose a trusted proficiency testing provider that will ensure you receive the best value before, during, and after your enrollment.

Is the Membership fee annual or one time?

The membership fee is billed annually and covers a full calendar year.  Many benefits are included with a membership, See "What are the benefits of Membership?" 

Why did I pass my preliminary report but fail my final report?

Your results will depend, in large part, upon the reference value assigned to the artifact(s) contained in the ILC/PT.  See “What are reference values?” question above for how NAPT obtains its reference values.  Since ILC/PTs are in constant circulation, it is necessary to periodically ensure that reference values have not changed.  In the case where an artifact is recalibrated and the reference value is found to have changed, participant data is reviewed to identify when the drift occurred.  If the drift is found to have occurred before your preliminary report was issued, your results will then be compared to the newly established reference values.  This may lead to a pass on your preliminary report, but a failure on your final report.

NAPT strives to minimize the impact of drift by selecting quality artifacts, scheduling regular pivot checks and monitoring data submitted by participants for any sudden changes in measurement data. 

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