ASTM E126-19 (2024) PDF

Full title and description

Standard Test Method for Inspection, Calibration, and Verification of ASTM Hydrometers — designation E126‑19 (reapproved 2024). Provides procedures, apparatus descriptions, and acceptance criteria for inspection, calibration, and verification of ASTM glass hydrometers (constant‑mass, variable‑displacement type).

Abstract

This test method describes the principles, required apparatus, reference materials, and step‑by‑step procedures to inspect, calibrate, and verify ASTM hydrometers used for measuring relative density/specific gravity. It is written for ASTM glass hydrometers but may be applied to other general hydrometers of comparable design, and includes notes on units (inch‑pound as standard, SI conversions for information).

General information

• Status: Active / Current (designation E126‑19; reapproved 2024).
• Publication date: May 1, 2024 (reapproval of the 2019 designation).
• Publisher: ASTM International.
• ICS / categories: 17.060 — Measurement of volume, mass, density, viscosity; ASTM section/volume: Temperature/volume measurement related collections.
• Edition / version: E126‑19 (original revision 2019) — reapproved 2024 (appears as E126‑19(2024)).
• Number of pages: 9 pages.

Scope

The standard applies to ASTM glass hydrometers and describes how to inspect physical condition, calibrate scale and graduation, and verify performance against reference standards. It addresses apparatus setup (bath, comparators, reference liquids), temperature control and correction, calibration checks across the scale, and reporting of results and uncertainties. The test method notes that inch‑pound units are primary and SI equivalents are for information only.

Key topics and requirements

• Inspection of hydrometer physical condition (bulb, stem, scale legibility, air bubbles).
• Calibration procedures for establishing graduation accuracy and zero/reference points.
• Verification methods using reference liquids or calibrated comparators and documentation of uncertainties.
• Temperature control, correction tables, and statement that inch‑pound units are standard (SI conversions informational).
• Acceptance criteria and reporting requirements for calibrated hydrometers (traceability to reference standards recommended).

Typical use and users

Used by calibration laboratories, instrument manufacturers and repair shops, quality assurance/quality control personnel in petroleum, chemical and laboratory testing environments, and by standards/metrology organizations performing routine verification or issuing calibration certificates.

Related standards

References and cross‑references commonly associated with this test method include other ASTM test methods and specifications for thermometers and density determination (for example, related ASTM procedures for thermometers and hydrometer use, and specific density test methods used in petroleum and laboratory practice). These cross‑references are listed within the standard itself.

Keywords

hydrometer, calibration, verification, inspection, reference standards, relative density, specific gravity, comparators, temperature correction, measurement uncertainty, ASTM E126.

FAQ

Q: What is this standard?

A: A test method (ASTM E126‑19) that defines how to inspect, calibrate, and verify ASTM glass hydrometers; reapproved in 2024 and published by ASTM International.

Q: What does it cover?

A: Procedures for physical inspection, calibration of graduations, verification against reference liquids/comparators, temperature control and correction, and reporting of calibration/verification results and uncertainties.

Q: Who typically uses it?

A: Calibration labs, instrument manufacturers/repairers, QA/QC personnel in industries using hydrometers (petroleum, chemicals, laboratories), and metrology/standards bodies.

Q: Is it current or superseded?

A: Current — designation E126‑19 was reapproved in 2024 (appears as E126‑19(2024)). Consult ASTM or an authorized distributor for the official PDF and any corrigenda or amendments.

Q: Is it part of a series?

A: It is part of ASTM’s collection of test methods covering liquid‑in‑glass instruments, density/relative density measurement, and related metrology procedures; cross‑references to other ASTM temperature and density standards appear in the document.

Q: What are the key keywords?

A: Hydrometer, calibration, verification, inspection, specific gravity, relative density, comparators, reference standards, measurement uncertainty.