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Balance and Scale Calibration and Uncertainties

This NIST Seminar will cover the calibration and use of analytical weighing instruments (balances and laboratory/bench-top scales), including sources of weighing errors in analytical environments, methodologies for quantifying the errors, and computation of balance calibration uncertainty and global (user) uncertainty. Attention will be given to error sources, selection of reference standards, and various calibration procedures used in the weighing industry. Approximately 50 percent of the time will be spent doing hands-on exercises, calibrating a variety of balances, accumulating data, and developing uncertainty budgets. The focus will then move to the use of balances in an analytical environment and regulatory environment where compliance with pharmaceutical (FDA/ USP) and international requirements will be discussed and practiced. Methodologies for process measurement assurance techniques in analytical weighing will also be covered. Participants will leave with a working skill-set of balance calibration methods, uncertainty estimation, measurement assurance concepts & minimum sample quantity computations that can be applied directly to their calibration and/or use of weighing instruments. This NIST Seminar is designed for beginner to advanced users of balances, metrologists, ISO/IEC 17025 assessors and accreditation bodies, or calibration managers wanting a better understanding of balances and associated uncertainties in organizations where analytical weighing is an integral part of operations. This seminar is limited to 12 participants. All participants will receive a comprehensive collection of national and international references and documents.

Learning Objectives:

At the end of this seminar, using your references and notes, you will be able to:

  • SUMMARIZE the principles and concepts of Measurement Traceability, Measurement Assurance, and Measurement Uncertainty.
  • EXPLAIN the interrelationships between traceability, measurement assurance, and measurement uncertainty.
  • SELECT the appropriate reference standards for the calibration of weighing instruments.
  • SELECT the appropriate international or national method/procedure for the calibration and/or use of weighing instruments in the ISO/IEC 17025 or regulatory environment.
  • DESCRIBE the NIST Eight-Step Process of Measurement Uncertainty Estimation applied to weighing instrument calibration and/or use
  • CONSTRUCT a procedure or outline for a balance calibration.
  • BRAINSTORM, CATEGORIZE, and QUANTIFY potential error sources and uncertainty contributors to weighing devices.
  • DEVELOP a basic uncertainty budget for weighing devices that is validated with the principles of measurement assurance.
  • ESTIMATE the minimum sample quantity for weighing instruments.

Materials & Supplies:

All materials and supplies provided by seminar hosts.


Read Euramet cg-18 before the seminar. The currently published version of cg-18 is found at:

After reading Euramet cg-18 it will become obvious that knowledge of basic and some advanced mathematics skills are needed to be successful in the Balance Calibration and Uncertainty Seminar. Complete and submit the 'Required To Know' math exercises below that contain evidence of mathematical skills you must have to be successful in the seminar: Required Mathematics Exercises. There is no planned review of these basic mathematics topics during the seminar.

It is also recommended that you complete the Recommended Math Exercises to enhance your participation in the seminar. These topics will be covered during the seminar, however early review will increase your understanding of the concepts.

Submit completed mathematics exercises for which you want feedback to val.miller [at] (val[dot]miller[at]nist[dot]gov). The provided feedback will let you know which topic areas need some review.

Below is a list of video resource's that will be helpful should you need review of the mathematics skills prior to the Balance Calibration & Uncertainty Seminar:

Minimum Requirement(s):

Successful completion requires that participants fully participate in all classroom and laboratory exercises, turn in or present accurate work assignments, and be present for the entire course, in addition to successfully completing the Balance Calibration Mathematical Exercises.


This NIST Seminar is designed for beginner to advanced users of balances or calibration managers wanting a better understanding of balances and associated uncertainties in organizations where analytical weighing is an integral part of operations.


The current fee for this seminar is $1,350. Registration fees for State weights and measures regulatory officials and metrologists are funded by NIST OWM. Payment is due by December 8, 2015.


Val Millerand Mark Reufenacht
Office of Weights and Measures,
(301) 975 - 3602
Email: val.miller [at] (val[dot]miller[at]nist[dot]gov)

Technology Requirement(s):

Laptop with spreadsheet capability and/ or scientific calculator strongly encouraged.


NIST / Office of Weights and Measures

CEUs Offered: 0.0

Class No. 5397

Time: 8:30 a.m. - 5:00 p.m. ET.

Registration Deadline: Thursday, November 19, 2015

Created September 30, 2015, Updated May 13, 2016