Scales Plus offers NIST traceable calibration reports for a majority of our scales and balances. One common question that comes up frequently from our customers: "Do I need a traceable calibration report?" The answer to this question as with most things, is 'it depends'.. From internal quality systems to legal for trade applications, the answer can get murky. 

The goal of this post is to explain what a NIST traceable calibration report is, who needs a calibration report, what a 'place in service' test is, and how they are different.

NIST Traceable Calibration Report

The National Institute of Standards and Technology defines traceability as a "...property of a measurement result whereby the result can be related to a reference through a documented unbroken chain of calibrations, each contributing to the measurement uncertainty." In layman's terms, each calibration weight has a cumulative uncertainty based on the traceable standards used to verify the test weights. Each weight Scales Plus uses is calibrated and certified by an NVLAP-accredited lab that allows our calibration technicians to provide a NIST traceable calibration report.

Each test by Scales Plus consists of dedicated procedures to ensure an accurate and repeatable process. After our technicians perform the calibration, they create a calibration certificate that reports the specific performance of the scale or balance. Before the traceable certificate is approved, a second Scales Plus technician reviews it and ensures that the information provided is correct. Scales Plus assigns your scale with an individual ID based on the serial number for simple tracking and recovery of data. Our technician then affixes a calibration sticker to the scale denoting the calibration date, the next due date, our technician's name and ID for easy record keeping. A paper copy of the report is also provided. If the copy of the certificate is lost, Scales Plus keeps the certificates on file electronically for easily retrieval.

Who uses a NIST Traceable Calibration Report?

At Scales Plus, we generally recommend a NIST traceable report for those customers who are not engaging in legal-for-trade activities and want quality assurance. States that participate in the National Type Evaluation Program (NTEP) usually require a legal-for-trade scale to be placed into service by a state weights and measures agent or licensed agency. Agents typically check, calibrate, and seal a scale used for sale-by-weight applications to prevent tampering. We'll discuss this later in this blog.

The most common reason a Scales Plus customer purchases a traceable calibration report is quality assurance. A scale that is out of calibration or damaged from the factory can lead to significant downtime and lost productivity. A calibration certificate provides assurances that the new scale performs within the manufacturer's specifications and is in proper working order. The test also verifies the calibration function works correctly.

Many ISO 9001 certified companies in manufacturing and other industries have extensive Quality Management Systems (QMS) that require calibrating equipment regularly. The most common calibration intervals are 90 days, 180 days, and annually. The calibration reports from Scales Plus have a 1-year recall date unless otherwise requested by the customer to fit their QMS procedures. We also have custom service plans for those customers who require more frequent calibrations. Ask a service representative for more information.

What does the phrase "Place-in-Service" mean?

As we briefly touched on earlier, legal-for-trade scales must meet strict requirements before selling items by weight from them. The certified or state technician performs tests specified by NIST Handbook 44 and documents the results. States participating in NTEP typically require filing additional paperwork, along with the sealing the scale. The lead seal prevents tampering or adjusting the calibration of a legal-for-trade scale to keep sales transactions fair for both the buyer and seller. The specific rules and test requirements can vary based on the state's current adopted rules and regulations.

The purpose of placing a scale into service is to protect the buyer and sellers by ensuring fairness.  The tests and paperwork prove that the scale is performing within the required tolerances outlined by Handbook 44. If the weight reading of a placed-in-service scale were significantly inaccurate, either higher or lower, the resulting sale would be unfair to one or both parties.

In many states, the weights and measures department send out technicians to test scales that were previously placed into service. If the state technicians fail a previously placed-into-service scale, then they red-tag the equipment, and a timeline for completing a repair and a new place-into-service test begins. Having a scale red-tagged highlights the importance of keeping up on service and calibrations for placed-in-service scales.

When is a scale placed into service?

All but four states in the US currently participate in NTEP. Generally, any scale that is NTEP-approved and used in direct sales requires a place-in-service test and sealing. The term direct sales describe transactions in which a seller calculates a monetary value based directly on the weight displayed on the scale. NIST Handbook 44 outlines explicitly the required test for each type of scale. Each state varies on what version of Handbook 44 they adopt, so make sure to check with your local weights and measures department before using a scale for direct sales.

Common examples of legal-for-trade scales are truck scales, floor scales, propane filling scales, deli scales, retail scales, jewelry, dispensary, and pharmacy balances. Handbook 44 outlines that for a scale to be placed in service, it must be classified as either Class I, II, III, IIII, or IIIL. The minimum and maximum divisions, along with the value of the verification division, determine the class. For example, any scale that has a verification division above 5 lbs and is between 2000 and 10,000 divisions is a class IIIL scale.

The Difference

Most notably, a state-certified technician must calibrate and seal NTEP scales used in legal-for-trade scenarios. In most cases, the scale must be onsite and connected to all peripherals before completing a place-in-service test. Once completed, a seller can legally use the scale for direct sales.

A traceable calibration report provides the end-user with a verification that the scale works to the manufacturer's specifications. The traceable calibration report is used as a quality check and for internal and external audits only and does not authorize the end-user to use the scale for direct sales. Scales Plus performs calibrations in our laboratory in Holland, Michigan. As such, the traceable reports we produce do not meet the requirements for NTEP scales used in direct sales.

For more information on place-in-service tests, legal-for-trade requirements, or traceable calibration reports, please contact the knowledgeable team at Scales Plus. Laws and regulations are ever-changing from state to state, and Scales Plus recommends checking with your local weights and measures department before making any decision regarding any legal-for-trade equipment purchases.