Recent progress at NPL in the development of mid-infrared spectrometric measurements

Frank J. J. Clarke; Christopher J. Chunnilall; Leon J. Rogers

doi:10.1117/12.509177

14 November 2003 Recent progress at NPL in the development of mid-infrared spectrometric measurements

Frank J. J. Clarke, Christopher J. Chunnilall, Leon J. Rogers

Proceedings Volume 5192, Optical Diagnostic Methods for Inorganic Materials III; (2003) https://doi.org/10.1117/12.509177
Event: Optical Science and Technology, SPIE's 48th Annual Meeting, 2003, San Diego, California, United States

Abstract

The National Physical Laboratory (NPL) realises and disseminates the UK spectrometric scales from 200 nm to 56 μm wavelength. Its mid-infrared (MIR) regular and hemispherical reflectance and transmittance scales, and transfer standards for the wavenumber and ordinate calibration of MIR spectrometers are realised from 2.5 μm to 56 μm using specially modified grating spectrometers. This paper will discuss a technique, recently developed at NPL, for the direct absolute realization of the hemispherical reflectance scale. This scale was previously based on a relative method using an absolutely calibrated mirror and published data for BaSO₄. The new method has given an improved value for the pure BaSO₄ to underpin the relative method. It opens up new applications as it can be applied to types of sample not previously measurable e.g. foil-covered insulation, and this aspect is discussed. The various sources of uncertainties are considered and the existing standards and services are also described briefly to place the technique in context. Although developed on grating instruments, this new measurement capability can be realized on Fourier transform (FT) spectrometers. Progress is being made at NPL in transferring its other MIR measurement capabilities to FT instrumentation. This will safeguard NPL’s future ability to provide these services to customers.

Citation Download Citation

Frank J. J. Clarke, Christopher J. Chunnilall, and Leon J. Rogers "Recent progress at NPL in the development of mid-infrared spectrometric measurements", Proc. SPIE 5192, Optical Diagnostic Methods for Inorganic Materials III, (14 November 2003); https://doi.org/10.1117/12.509177

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available