Standards Development

Scope

This document specifies the requirements for the laminated-type reference mirrors consisting of an Ag or Al metal thin film layer used for relative measurements of regular spectral reflectance of fine ceramic coatings day-to-day in laboratory room or quality assurance rooms.

Purpose

The evaluation of reflectance of fine ceramic coating is one of the important characterizations in their industrial applications. Although there are some methods to measure the absolute reflectance of plane surfaces, such as the V-N method, the V-W method, or the -2 optics method, in industries, the method measuring the relative reflectance by using a reference mirror is widely used in industries. For the method for measuring the relative reflectance by using a reference mirror, the use of the reference mirrors with a long-term stability in the ambient air is one of important factors for the reliability of the reflectance measurements.

The reference mirrors for the reflectance measurements are, in general, consisted of an over-coated Ag or Al metal thin film due to their high reflectance in the UV-visible and near IR regions. However, because Ag and Al metals are strongly corrosive against the environment containing Cl2 and SO2, which are most common corrosive gases in the circumstances in the factory laboratory or quality assessment rooms, the use of the quality-ensured reference mirrors are mandatory for the day-to-day measurements of the relative reflectance of fine ceramic coatings.

Laminated-type Ag or Al reference mirrors possess much higher stability compeered to an Ag- or Alcoated single-glass-plate type reference mirror against the corrosive gases and are beneficial to the day-to-ay use as a reference mirror in the measurements of regular spectral reflectance of fine ceramic coatings.

To date, no standard has been published concerning the requirements for the laminated-type reference mirrors consisting of an Ag or Al metal thin film layer.

This document specifies the requirements for laminated-type Ag or Al mirrors for the day-to-day use as a reference mirror for regular spectral reflectance measurements. This document has been enacted to facilitate industrial development through the prompt dissemination of these measurement methods.