1.1本指南描述了以摄氏度或华氏度或两者为单位提供温度读数的通用数字接触温度计（以下简称“数字温度计”）。描述了这些温度计的不同类型的温度传感器，并讨论了它们的相对优点。介绍了数字温度计的九种精度等级；这些类别考虑了传感器/测量仪器单元的精度。 1.2数字温度计的拟议精度等级涉及-200°C至500°C的温度区间，这是一个对测温中的许多应用特别感兴趣的区间。所讨论的数字温度计的所有温度传感器类型都能够在该间隔内至少在某个范围内测量温度。有些类型也可以测量超出此间隔的值。为了达到精度等级，温度计必须在此间隔或其能够进行测量的子间隔内正确测量到规定值（以°C为单位）。 那些可以在超过该间隔的范围内测量温度的温度计通常在这些范围内具有较大的测量不确定度。 1.3讨论的数字温度计传感器是铂电阻传感器、热敏电阻和热电偶。提供了这些类型传感器的使用范围。传感器的测量不确定度由其公差等级或等级以及传感器是否已校准决定。 1.4本指南为数字温度计的制造和选择提供了一些建议。首先，建议温度计的传感器符合适用的ASTM规范。此外，它还建议了温度计文件的最低标准以及探针和测量仪器上的信息标记。 1.5本指南中导出的国际单位制（摄氏度）应视为标准。然而，只要遵循所有其他指南，显示华氏度的温度计就符合本指南。 1.6 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前建立适当的安全和健康实践，并确定监管限制的适用性。第7节“危险”中给出了一些具体的危险说明。 ====意义和用途====== 4.1数字温度计用于测量许多实验室和工业应用中的温度。 4.2对于许多应用，使用外部探头的数字温度计被认为是玻璃汞温度计的环境安全替代品。 ( 1. ) 3. 4.3在检定和校准温度计以及确定评估法定计量和工业中使用的其他测量仪器性能所需的条件时，一些数字温度计也用作参考或工作温度标准。

1.1 This Guide describes general-purpose, digital contact thermometers (hereafter simply called “digital thermometers”) that provide temperature readings in units of degrees Celsius or degrees Fahrenheit, or both. The different types of temperature sensors for these thermometers are described, and their relative merits are discussed. Nine accuracy classes are introduced for digital thermometerhes; these classes consider the accuracy of the sensor/measuring-instrument unit. 1.2 The proposed accuracy classes for digital thermometers pertain to the temperature interval of –200 °C to 500 °C, an interval of special interest for many applications in thermometry. All of the temperature sensor types for the digital thermometers discussed are able to measure temperature over at least some range within this interval. Some types are also able to measure beyond this interval. To qualify for an accuracy class, the thermometer must measure correctly to within a specified value (in units of °C) over this interval or over the subinterval in which they are capable of making measurements. Those thermometers that can measure temperature in ranges beyond this interval generally have larger measurement uncertainty in these ranges. 1.3 The digital thermometer sensors discussed are platinum resistance sensors, thermistors, and thermocouples. The range of use for these types of sensors is provided. The measurement uncertainty of a sensor is determined by its tolerance class or grade and whether the sensor has been calibrated. 1.4 This Guide provides a number of recommendations for the manufacture and selection of a digital thermometer. First, it recommends that the thermometer’s sensor conform to applicable ASTM specifications. Also, it recommends minimum standards for documentation on the thermometer and informational markings on the probe and measuring instrument. 1.5  The derived SI units (degrees Celsius) found in this Guide are to be considered standard. However, thermometers displaying degrees Fahrenheit are compliant with this guide as long as all other guidance is followed. 1.6 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. Some specific hazards statements are given in Section 7 on Hazards. ====== Significance And Use ====== 4.1 Digital thermometers are used for measuring temperature in many laboratories and industrial applications. 4.2 For many applications, digital thermometers using external probes are considered environmentally-safe alternatives to mercury-in-glass thermometers. ( 1 ) 3 4.3 Some digital thermometers are also used as reference or working temperature standards in verification and calibration of thermometers and also in determining the conditions necessary for evaluating the performance of other measuring instruments used in legal metrology and industry.