ASME B89.6.2-1973 (2017) PDF

Full title and description

ASME B89.6.2-1973 (R2017) — Temperature and Humidity Environment for Dimensional Measurement. This standard provides definitions, test methods and acceptance guidelines for temperature- and humidity-controlled environments used for precision dimensional measurement, calibration of measuring equipment, and the manufacture or acceptance of workpieces where environmental effects can influence dimensional results.

Abstract

ASME B89.6.2 establishes how to describe and test temperature-controlled and humidity-controlled environments for dimensional metrology. It includes general requirements and definitions, procedures for measuring and characterizing environmental conditions, tests to demonstrate adequacy of control (including calculation of thermal time constants, "soak‑out" time, and a thermal error index), and guidance to assure that environmental control is sufficient for calibration and measurement purposes. The document also contains an appendix with historical background and recommended temperatures for dimensional standards.

General information

• Status: Active / Reaffirmed (stabilized maintenance).
• Publication date: Original: January 14, 1973. Reaffirmation (R2017): 2017 (reconfirmation placed the 1973 edition on stabilized maintenance).
• Publisher: American Society of Mechanical Engineers (ASME).
• ICS / categories: Metrology / Dimensional measurement; Geometrical product specification and verification (ICS 17 — metrology-related categories).
• Edition / version: B89.6.2 — 1973 (R2017) (original 1973 edition, reaffirmed 2017).
• Number of pages: 31 pages (approx.).

Scope

The standard covers methods for describing, testing and assuring temperature and humidity conditions in spaces used for dimensional measurement and calibration. It defines required measurements and test procedures for establishing environmental stability and uniformity, sets out procedures to compute thermal time constants and thermal error indices for equipment and artifacts, and provides acceptance guidance so that labs and production facilities can verify that their environmental control is adequate for the intended level of dimensional accuracy. The scope is aimed at both laboratory and shop-floor measurement situations where environmental effects cannot be neglected.

Key topics and requirements

• Definitions and general requirements for environmental control for dimensional measurement (temperature and relative humidity).
• Procedures for characterizing and testing the environment (uniformity, stability, gradients and transient behavior).
• Methods for determining thermal time constants ("soak‑out" time) of instruments and artifacts.
• Calculation and use of a thermal error index to quantify environmental impacts on measurement.
• Guidance to assure environmental control is adequate for calibration, inspection and manufacturing acceptance.
• Appendix material including historical background and recommended reference temperatures for dimensional standards.

Typical use and users

Used by calibration laboratories, metrology / quality engineers, CMM and dimensional inspection labs, instrument manufacturers, and companies that perform precision manufacturing or acceptance testing. Typical applications include setting requirements for CMM rooms, calibration labs, gauge rooms, and controlled enclosures; verifying environmental suitability before high‑precision measurements; and documenting environmental test procedures for audits and accreditation.

Related standards

Commonly referenced or complementary standards include ISO 1 (standard reference temperature for geometrical and dimensional properties — 20 °C), ASME/ANSI Y14.5 (dimensioning and tolerancing practices that assume a reference temperature), ISO/IEC 17025 (laboratory accreditation requirements that include environmental control considerations), and standards for CMM performance and verification (for example ISO 10360 series and ASME B89 series on CMMs and indicators). Users should consult these documents when implementing measurement systems and uncertainty budgets.

Keywords

Temperature control, Humidity control, Dimensional measurement, Metrology, Calibration environment, Thermal time constant, Soak-out time, Thermal error index, CMM room, Reference temperature (20 °C).

FAQ

Q: What is this standard?

A: ASME B89.6.2-1973 (R2017) is an ASME standard that specifies how to describe, test and verify temperature and humidity environments used for precision dimensional measurement and calibration.

Q: What does it cover?

A: It covers definitions, general requirements, test procedures for environment characterization (stability, uniformity, gradients), calculations for thermal time constants and thermal error indices, and guidance for assuring environmental adequacy for calibration and measurement tasks.

Q: Who typically uses it?

A: Calibration labs, metrology engineers, quality/control departments, CMM operators, gauge manufacturers and anyone responsible for establishing or verifying the measurement environment for high‑precision dimensional work.

Q: Is it current or superseded?

A: The 1973 edition was reaffirmed in 2017 (designated B89.6.2:1973 (R2017)) and has been placed on stabilized maintenance; that reaffirmation indicates the document remains in effect unless and until revised. Users should check ASME for the latest status before relying on it for procurement or compliance.

Q: Is it part of a series?

A: It belongs conceptually to the ASME B89 family of standards on dimensional metrology and is often used alongside other ASME/ANSI and ISO standards dealing with dimensional measurement, instrumentation and reference temperatures.

Q: What are the key keywords?

A: Temperature control, humidity control, dimensional measurement, metrology, calibration environment, thermal time constant, thermal error index, reference temperature (20 °C).