Fundamental measurement techniques

Abstract

Publisher Summary Fire testing relies on fundamental measurements of physical quantities such as temperature, pressure, flow rate, mass, etc. This chapter provides an overview of the fundamental measurement techniques that are commonly used in support of flammability testing of materials. It also discusses some of the challenges that need to be overcome to perform accurate measurements. Thermocouples are by far the most commonly used sensors to measure temperature in fire tests. Objects that are exposed in a room fire environment are heated by the radiation from flames, combustion gases, and hot surfaces. A slug calorimeter is the most basic device to measure heat flux in fire tests. Also, the most commonly used type of sensors to measure the mass of a burning object is the load cell. Load cells come in many forms and shapes to facilitate their use for a wide range of applications. The objective of a measurement is to determine the value of the measurand, i.e., the physical quantity that needs to be measured. Every measurement is subject to error, no matter how carefully it is conducted. Errors of measurement may have two components, a random component and a systematic component. The former is due to a number of sources that affect a measurement in a random and uncontrolled manner. Random errors cannot be eliminated, but their effect on uncertainty may be reduced by increasing the number of repeat measurements and by applying a statistical analysis to the results.