ASTM E2540-16 (2022) PDF

Full title and description

Standard Test Method for Measurement of Retroreflective Signs Using a Portable Retroreflectometer at a 0.5 Degree Observation Angle — designation E2540‑16 (Reapproved 2022). This ASTM test method defines the procedure and instrument geometry for field measurement of the retroreflective properties of vertical sign materials (traffic signs and symbols) using a hand‑held portable retroreflectometer operating with a 0.5° observation angle.

Abstract

This standard specifies how to place, standardize, and read a portable retroreflectometer in contact with sign face materials to obtain a measurement of coefficient of retroreflection (retroreflective brightness) at a 0.5° observation angle and defined entrance geometry. It is intended primarily for field measurements of in‑service traffic signs (and for pre‑placement verification of materials) so results can be compared to minimum performance requirements and used to schedule maintenance or replacement.

General information

• Status: Reapproved 2022 (designation E2540‑16; current as reapproved February 1, 2022).
• Publication date: February 1, 2022 (current reapproval date).
• Publisher: ASTM International (Committee E12 on Color and Appearance; Subcommittee E12.10 on Retroreflection).
• ICS / categories: 93.080.40 (street lighting and related equipment / road equipment and installations).
• Edition / version: E2540‑16 (original 2016 designation, reapproved 2022).
• Number of pages: 7 pages.

Scope

The test method covers measurement of the retroreflective properties of sign materials (vertical surfaces) using a hand‑held portable retroreflectometer with a defined standard geometry. Measurements are made in contact with the sign material and reported in SI units; entrance and observation angles follow the U.S. practice described in the document and may differ from angles used elsewhere. The method is intended for field measurement of in‑service traffic signs and may also be used for pre‑installation verification of sign materials. Safety, health and environmental considerations are the responsibility of the user.

Key topics and requirements

• Measurement geometry: 0.5° observation angle (with specified entrance angle) for portable retroreflectometer measurements.
• Use of a portable, hand‑held retroreflectometer placed in contact with sign face; instrument standardization before measurement.
• Reporting in SI units; multiple readings on a sign face and averaging to assess in‑service performance.
• Purpose: determine night‑time brightness relevant to driver visibility (measurements relate to perceived brightness for a mid‑sized automobile driver using tungsten‑type headlamps at practical viewing distances used in the standard).
• Application: field condition assessment, QA/QC of sign materials, and scheduling replacement due to material degradation.
• Normative links: references to other ASTM practices/terminology used by Committee E12 (e.g., practices describing photometry and retroreflection terminology).

Typical use and users

Typical users include transportation agencies and departments of transportation, municipal sign maintenance crews and inspectors, sign manufacturers and materials suppliers (for acceptance/QA), contractors performing field surveys, and laboratories conducting retroreflectivity audits. The method is used to determine whether in‑service signs meet minimum retroreflective performance and when replacement is needed.

Related standards

Closely related documents commonly referenced with E2540 include ASTM D4956 (specification for retroreflective sheeting for traffic control), ASTM E1709 (portable retroreflectometer method at 0.2° observation angle) and ASTM E809 (practice for measuring photometric characteristics of retroreflectors), along with other E12 committee practices and test methods that define terminology and photometric measurement procedures. These documents together provide the specification, alternate measurement geometries, and photometric context for retroreflective sign evaluation.

Keywords

retroreflective, retroreflection, portable retroreflectometer, 0.5° observation angle, traffic signs, field measurement, coefficient of retroreflection, annular geometry, sign maintenance, E12.10.

FAQ

Q: What is this standard?

A: ASTM E2540‑16 (Reapproved 2022) is a Standard Test Method that defines how to measure the retroreflective properties of traffic sign materials using a portable retroreflectometer at a 0.5° observation angle.

Q: What does it cover?

A: It covers the procedure, instrument geometry, measurement practice (contact measurements with a hand‑held device), reporting in SI units, and use of results to compare against performance requirements for traffic signs (field and pre‑placement checks).

Q: Who typically uses it?

A: Transportation agencies, sign maintenance personnel, manufacturers and suppliers of retroreflective sheeting, contractors and testing labs perform measurements under this method for QA/QC, compliance checks, and sign replacement decisions.

Q: Is it current or superseded?

A: The document carries the designation E2540‑16 and was reapproved (reaffirmed) in 2022; it is the current reapproval of the 2016 edition (reapproved Feb 1, 2022). Users should check ASTM records for any later revisions or withdrawals.

Q: Is it part of a series?

A: Yes — E2540 is part of a family of ASTM E12/E12.10 documents on retroreflection and photometry. Related methods include E1709 (0.2° portable measurement) and practices such as E809 (photometric measurement practice); specification documents for materials (e.g., D4956 for retroreflective sheeting) are commonly used in conjunction.

Q: What are the key keywords?

A: Key keywords are: retroreflective, retroreflection, portable retroreflectometer, coefficient of retroreflection, observation angle 0.5°, traffic sign measurement, field test method.