Significance and Use
4.1 The purpose of these test methods is to establish consensus test methods by which both manufacturers and end users may perform tests to establish the validity of the readings of their radiation thermometers. The test results can also serve as standard performance criteria for instrument evaluation or selection, or both.
4.2 The goal is to provide test methods that are reliable and can be performed by a sufficiently skilled end user or manufacturer. It is hoped that it will result in a better understanding of the operation of radiation thermometers and also promote improved communication between the manufacturers and the end users. A user without sufficient knowledge and experience should seek assistance from the equipment makers or other expert sources, such as those found at the National Institute of Standards and Technology in Gaithersburg, Maryland.
4.3 These test methods should be used with the awareness that there are other parameters, particularly spectral range limits and temperature resolution, which impact the use and characterization of radiation thermometers and for which test methods have not yet been developed.
4.3.1 Temperature resolution is the minimum simulated or actual change in target temperature that results in a usable change in output or indication, or both. It is usually expressed as a temperature differential or a percent of full-scale value, or both, and usually applies to value measured. The magnitude of the temperature resolution depends upon a combination of four factors: detector noise equivalent temperature difference (NETD), electronic signal processing, signal-to-noise characteristics (including amplification noise), and analog-to-digital conversion “granularity.”
4.3.2 Spectral range limits are the upper and lower limits to the wavelength band of radiant energy to which the instrument responds. These limits are generally expressed in micrometers (μm) and include the effects of all elements in the measuring optical path. At the spectral response limits, the transmission of the measuring optics is 5 % of peak transmission. (See Fig. 1.)
FIG. 1 Spectral Range Limits
Scope
1.1 The test methods described in these test methods can be utilized to evaluate the following six basic operational parameters of a radiation thermometer (single waveband type):
Section
Calibration Accuracy
8
Repeatability
9
Field-of-View
10
Response Time
11
Warm-Up Time
12
Long-Term Stability
13
1.2 The term single waveband refers to radiation thermometers that operate in a single band of spectral radiation. This term is used to differentiate single waveband radiation thermometers from those termed as ratio radiation thermometers, two channel radiation thermometers, two color radiation thermometers, multiwavelength radiation thermometers, multichannel radiation thermometers, or multicolor radiation thermometers. The term single waveband does not preclude wideband radiation thermometers such as those operating in the 8–14 μm band.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
