BS 1041-5:1989

Foreword
Committees responsible
Guide
0 Introduction
1 Scope
2 Definitions
3 Principles of radiation pyrometry
3.1 Introduction
3.2 The laws of radiation
3.3 Emissivity
3.4 The emissivity of materials
3.5 Radiation exchange and emissivity errors
3.6 Colour temperature and ratio pyrometers
3.7 Effective wavelength
4 Advantages and limitations of radiation
         pyrometers
4.1 Introduction
4.2 Advantages
4.3 Limitations
5 Classification of radiation pyrometers
5.1 Introduction
5.2 Classification by wavelength selection
         principle
5.3 Classification by method of operation: direct-
         reading and comparison pyrometers
6 Principal types of radiation pyrometer
6.1 Total and broadband pyrometer
6.2 Narrow band, or spectral, pyrometers
6.2.1 Photoelectric pyrometers
6.2.2 Visual pyrometers
6.2.3 Ratio pyrometers
6.3 Emissivity and background compensation
6.3.1 Emissivity compensated pyrometers for
         specularly reflecting surfaces
6.3.2 Emissivity compensation using a hemispherical
         reflector
6.3.3 Two-sensor pyrometry
6.3.4 The use of cavities
7 Detectors
7.1 General
7.2 Detector characteristics
7.2.1 Properties
7.2.2 Sensitivity and noise
7.2.3 Stability
7.2.4 Response time
7.3 Types of detector
7.3.1 The eye as a detector
7.3.2 Thermal detectors
7.3.2.1 General
7.3.2.2 Pyroelectric detectors
7.3.3 Photon detectors
7.3.3.1 Photoemissive detectors
7.3.3.2 Semiconductor detectors
8 Optical systems
8.1 Introduction
8.2 Aperture optics
8.3 Lens optics
8.4 Mirror optics
8.5 Fibre optics
8.6 Sighting
9 Signal treatment
10 Calibration
10.1 Introduction
10.2 The ITS-90
10.3 Blackbody sources
10.4 Standard lamps
10.5 Transfer standard pyrometers
10.6 Uncertainties and procedures
11 Precautions necessary in the use of radiation
         pyrometers
11.1 Factors affecting indicated temperature
11.2 Process monitoring
11.3 Installation
11.4 Absorption by the intervening medium
11.5 Emissivity
Tables
1 Transmission of lens and window materials
2 Typical emissivity values (for guidance only)
3 Variations of radiance temperature with
         pyrometer effective wavelength and with
         emissivity
4 Errors in temperature arising from an error of
         - 10 % in emissivity at three effective
         wavelengths
Figures
1 Spectral radiance of a blackbody as a function
         of wavelength and temperature
2 Schematic arrangement of a pyrometer D, and a
         radiating surface R in surroundings S
3 Optical system for diappearing filament optical
         pyrometer
4 The visibility function, A, and the
         transmission of a typical red glass, B
5 Relative spectral sensitivities of some photon
         detectors
6 Diagram of an aperture optical system
7 Diagram of a lens optical system
8 Diagram of a single mirror optical system
9 Diagram of a Cassegrain optical system
10 Fibre optic pyrometer sighted on an
         inaccessible target
11 Fibre optic pyrometer in a hostile environment
12 Corrections for wavelength changes in lamp
         calibration at 650 nm

Guidance on the principles of radiation pyrometry, the classification and types of radiation pyrometers, their calibration and the precautions necessary in their use.

This Part of BS 1041 gives guidance on the selection of radiation pyrometers for use in scientific and industrial environments.

NOTE The titles of the publications referred to in this guide are listed on the inside back cover.