We offer an optional NIST certificate for our infrared thermometers. Read this article to learn more about NIST and NIST certificates, NIST traceability, and to decide whether a NIST certified unit is right for your needs.
NIST – The National Institute of Standards and Technology
Let’s start by explaining what NIST means. NIST is the National Institute of Standards and Technology, a physical science laboratory that is part of the U.S. Department of Commerce. It was founded in 1901 and is one of the nation’s oldest physical science laboratories. Its main purpose and mission is to develop and maintain measurement standards. As part of that mission, NIST provides certified standard reference materials (SRMs) allowing science and industry to achieve more accurate measurements.
NIST Certificates
A NIST certificate is a document that certifies that your product has been tested against reference standards and/or tested with NIST-traceable instruments and that it meets or exceeds its specifications. A NIST certificate states that the product was found to be within its stated tolerance of accuracy. It also documents the environmental conditions at the time of testing, which equipment or standard reference materials were used, and some NIST certificates provide the actual test data as well. You can see a sample of our NIST certificate here.
NIST Traceability
A NIST traceable product is a product that was tested with equipment that has an unbroken chain of traceability to NIST standards. That means that every calibration instrument used for NIST certification has to have a valid NIST certificate itself, which may have been obtained by comparing its calibration against another NIST traceable instrument and so on, eventually leading back to a standard reference material certified by NIST. Instruments used for NIST certification must get tested and re-certified at regular intervals, typically annually.
Comparing measurements of a test unit against a reference material is the preferred method of verification since it eliminates the measurement uncertainty that comes with a chain of traceable instruments. An example is the ice point of 0°C, established with a temperature controlled ice bath and used for calibrating or testing thermometers. However, the practical use of SRMs is often limited, and NIST traceable instruments have to be used instead to characterize the test unit at multiple points across its measurement range.
Do you need a NIST certificate?
In short, a NIST certificate documents the accuracy of your instrument and that it meets its specifications. Let’s look at some cases when you would want one.
Most often, NIST certificates are requested for regulatory compliance purposes. For example, restaurants or food banks may be required to have a NIST certificate for the thermometer they use to test the temperature of food.
Some industries may require NIST certificates for their instruments to meet the documentation requirements of ISO compliance. Or scientists may wish to maximize the measurement accuracy for a critical experiment, and having a NIST certificate with test data available gives them more detailed information on the measurement error of their instrument.
You may also want a NIST certificate to simply know that your unit was tested and found to be accurate before it was shipped.
Please know that not all of our IR thermometers are shipped with NIST certificates. You have to purchase the product that explicitly states “…with NIST certificate”. The standard units we sell do not come with NIST certificates.
Also, because of the additional testing and documentation required to generate a NIST certificate, we cannot offer a NIST certificate for a standard unit you already purchased. We can only issue NIST certificates for units that have gone through the process of testing required to issue the certificates. If you intended to purchase a NIST certified unit and purchased a standard unit by accident, please contact us at [email protected] to discuss an upgraded replacement.
The NIST Certification Process
The process of NIST-certifying an infrared thermometer starts with a complete visual and functional check to make sure the unit does not have any defects. This is followed by a temperature test to record the exact readings at different temperatures. Our standard NIST certification includes the following three temperatures: 0°C (32°F), room temperature, and 100°C (212°F). They are the temperatures of most interest to the majority of applications including food safety. We also offer certification at custom temperatures.
To test the accuracy at 0°C (32°F) we use a temperature-controlled crushed ice bath. For tests at higher temperatures up to 500°C (932°F), we use infrared calibrators (IR-500 and BR-M400) and probe-type reference thermometers (DTU6005-002-N from QTI Sensing Solutions and Precision Plus Thermometer by Thermoworks). Our infrared calibrators and reference thermometers are all traceable to NIST and calibrated annually by an ISO 17025 accredited calibration laboratory.
Even though our in-house calibration laboratory is not ISO 17025 accredited, we are well aware of the structural, process and management requirements outlined in the ISO 17025 documentation and follow its guidelines to make sure our test and quality control system produces accurate and consistent results, and all data and records are stored securely and with backups.
In some cases, regulations may require you to obtain a NIST certificate from an ISO 17025 accredited laboratory. If that applies to you, you need to contact a third party calibration lab that is accredited under ISO 17025 to get your product NIST certified.
Calibration Interval and Re-Certification
How long is your NIST certificate valid? The short answer is: typically for one year, after which you need to get your unit re-certified and re-calibrated, if needed (re-calibration is included in the cost of re-certification). Depending on your application and requirements, you may choose to have your unit checked and re-certified by us more frequently. The time between re-certifications is called the calibration interval.
Keep in mind that this calibration interval, the period for which your NIST certificate is valid, does not start with the date on the NIST certificate. It starts on the date the unit is placed into service. Our thermometers typically do not undergo changes in accuracy between the time of calibration and the time they are placed into service (i.e. during shipment and storage).
Also, please note that although the measurement results provided on the NIST certificate can be considered to be traceable to NIST reference standards at the time the measurements were performed, we cannot certify that those measurement results are valid after the instrument has been returned to you and placed into service. You or the responsible party in your organization must have an appropriate internal measurement assurance program in place to assure the continued validity of these measurement results. This program should also specify a calibration interval appropriate for your application. The recommended calibration interval for our thermometers for general industrial and laboratory use is one year.
Should you discover, through your internal measurement assurance program, that your thermometer seems to give inaccurate readings, please contact us to get your unit re-calibrated. Calibration of IR thermometers requires proper equipment, good knowledge and experience of how to use it and its limitations, and knowledge of the exact sequence and methodology of the calibration process itself. We currently do not provide calibration instructions to customers or third party laboratories.
We charge $50 per unit for re-certifcation/re-calibration. You pay to ship your unit to us, and we cover the return shipping costs. This process takes up to 10 business days. To get your NIST-traceable infrared thermometer re-certified, you can purchase this service on our website by visiting the following link:
NIST Re-Certification of ennoLogic IR Thermometers – Click Here to Start Process
