ASTM D5032-19 PDF

Full title and description

ASTM D5032-19 — Standard Practice for Maintaining Constant Relative Humidity by Means of Aqueous Glycerin Solutions. This practice describes a simple, small‑scale method for producing stable relative humidity (RH) environments using aqueous glycerin solutions, intended for conditioning specimens or materials in closed containers for shelf‑life, dielectric, or physical property studies.

Abstract

This practice specifies preparations and procedures for obtaining constant relative humidity values between about 30 % and 98 % at temperatures from 0 °C to 70 °C in relatively small, closed containers by use of aqueous glycerin solutions. It highlights advantages of glycerin solutions (reduced contamination and reduced corrosion risks compared with some salt or acid solutions) and gives guidance on applicability and limitations (for example, it is not recommended for generating continuous flowing humidity streams without precautions).

General information

• Status: Active.
• Publication date: January 3, 2019 (designated -19).
• Publisher: ASTM International (ASTM).
• ICS / categories: 07.060 (Geology/Meteorology/Hydrology); 91.140.30 (Ventilation and air‑conditioning systems).
• Edition / version: D5032-19 (2019 revision of earlier D5032 editions).
• Number of pages: 3 pages.

Scope

This practice describes a method for obtaining constant RH values from about 30 % to 98 % at temperatures from 0 °C to 70 °C in relatively small, closed conditioning containers by means of aqueous glycerin solutions. It is intended for closed systems (environmental conditioning containers) and is not recommended for generating continuous flowing streams of humidity unless additional stability precautions are followed. Applicable material specifications should state the exposure conditions (time, temperature, RH) required for subsequent testing.

Key topics and requirements

• Preparation and use of aqueous glycerin solutions to establish target RH levels (typical RH range: ≈30–98 %).
• Operating temperature range for the practice: 0 °C to 70 °C.
• Applicability limited to relatively small, closed containers (environmental conditioning containers).
• Recommendations and cautions about using glycerin solutions versus saturated salt or acid solutions (reduced risk of contamination and corrosion).
• Guidance that continuous flowing humidity streams are not recommended without verifying source stability and taking precautionary measures.
• References to material‑conditioning specifications and related practices that should define exact exposure conditions (time, temperature, RH) for downstream tests.

Typical use and users

Laboratories and quality‑control groups in materials science, electronics, packaging, conservation, and polymer testing commonly use this practice to condition samples at fixed humidity levels before physical, chemical, or dielectric testing. Users include research laboratories, product development groups, environmental test labs, museums/conservation facilities (for material ageing studies), and manufacturers performing shelf‑life or humidity sensitivity evaluations.

Related standards

Relevant documents and related ASTM practices include Practice D618 and Practice D6054 (for conditioning and specifying exposure conditions) and earlier revisions of this practice (ASTM D5032-11 and ASTM D5032-97). The practice sits within Book of Standards volume and committee D09 (Subcommittee D09.12 developed the practice).

Keywords

aqueous glycerin solutions, relative humidity, constant RH, environmental conditioning, humidity generation, specimen conditioning, glycerin, closed container conditioning, material ageing.

FAQ

Q: What is this standard?

A: ASTM D5032-19 is a short ASTM practice that describes how to create and maintain constant relative humidity environments in relatively small, closed containers using aqueous glycerin solutions for conditioning specimens prior to testing.

Q: What does it cover?

A: It covers preparation and use of aqueous glycerin solutions to obtain stable RH from about 30 % to 98 % over the temperature range 0 °C to 70 °C in closed containers, plus applicability limits and cautions (for example, not recommended for continuous flowing humidity generation without additional controls).

Q: Who typically uses it?

A: Test and QA laboratories, materials scientists, packaging and electronics manufacturers, conservators, and anyone who needs to condition samples at controlled humidity in small environmental chambers or closed containers prior to physical, chemical, or electrical testing.

Q: Is it current or superseded?

A: The -19 revision (published January 3, 2019) is the current published revision (revises D5032-11 and earlier editions). Users should confirm any later revisions or withdrawals with ASTM if up‑to‑date status is critical.

Q: Is it part of a series?

A: Yes — D5032 is a standalone practice with earlier editions (for example D5032-11 and D5032-97). It is commonly used alongside other conditioning and environmental practices such as D618 and D6054 that specify exposure conditions for materials testing.

Q: What are the key keywords?

A: aqueous glycerin solutions; constant relative humidity; humidity generation; conditioning; closed container; environmental conditioning; glycerin; specimen conditioning.