What is a requirement for a thermometer in concrete testing?

The requirement for a thermometer in concrete testing includes having a range of at least 30-120°F and the capability of being readable to the nearest 1°F. This is crucial because the temperature of the concrete can significantly impact its setting time, strength development, and overall performance.

Concrete can be poured in a variety of environmental conditions, and temperature variations can affect how quickly the concrete sets. A thermometer that accurately reads within this specified range ensures that testers can monitor conditions effectively and make informed decisions regarding curing and placement times. The readability to the nearest 1°F provides sufficient precision for practical field measurements without complicating the process, which is vital for ensuring consistency and reliability in testing.

Other options may not meet the necessary technical specifications for effective concrete temperature measurement, leading to potential errors in evaluating the concrete's performance under varying conditions. The established range and accuracy ensure reliable results, which are integral to maintaining quality control in concrete construction.