Applications—Ambient atmospheric temperature measurements can be made using resistance thermometers for many purposes. The application determines the most appropriate type of resistance thermometer and data recording method to be used. Examples of three typical meteorological applications for temperature measurements follow.

Single-level, near-surface measurements for weather observations (1) , thermodynamic computations for industrial applications, or environmental studies (2).

Temperature differential or vertical gradient measurements to characterize atmospheric stability for atmospheric dispersion analyses studies (2).

Temperature fluctuations for heat flux or temperature, or variance computations, or both. Measurements of heat flux and temperature variance require high precision measurements with a fast response to changes in the ambient atmosphere.

Purpose—This practice is designed to assist the user in selecting an appropriate temperature measurement system for the intended atmospheric application, and properly installing and operating the system. The manufacturer's recommendations and the U.S. Environmental Protection Agency handbook on quality assurance in meteorological measurements (3) should be consulted for calibration and performance audit procedures.

1. Scope

1.1 This practice provides procedures to measure representative near-surface atmospheric (outdoor air) temperature for meteorological purposes using commonly available electrical thermometers housed in radiation shields mounted on stationary or portable masts or towers.

1.2 This practice is applicable for measurements over the temperature range normally encountered in the ambient atmosphere, –50 to +50°C.

1.3 Air temperature measurement systems include a radiation shield, resistance thermometer, signal cables, and associated electronics.

1.4 Measurements can be made at a single level for various meteorological purposes, at two or more levels for vertical temperature differences, and using special equipment (at one or more levels) for fluctuations of temperature with time applied to flux or variance measurements.

1.5 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 and health practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

D1356 Terminology Relating to Sampling and Analysis of Atmospheres

E344 Terminology Relating to Thermometry and Hydrometry

E644 Test Methods for Testing Industrial Resistance Thermometers

E1137/E1137M Specification for Industrial Platinum Resistance Thermometers

Keywords

air temperature; platinum resistance thermometer; resistance thermometer; solar and terrestrial radiation shields; thermistor; Air temperature; Electrical temperature sensors; Platinum resistance thermometers (PRT); Resistance thermometers; Sensors; Solar radiation shields; Surface analysis--atmospheric; Terrestrial radiation shields; Thermistor sensors;

ICS Code

ICS Number Code 17.200.20 (Temperature-measuring instruments)

Citing ASTM Standards

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