Defining the thermal environment in fire tests

The ability of engineered systems to withstand a fire environment is usually demonstrated by test. Iterative design and experimentation historically has been used to develop these engineered systems. To optimize the engineered system, in instances where the cost of the prototype is high, the process of iterative redesign and testing may be infeasible. Consequently, in such instances it is desirable to predict the thermal performance of the engineered system analytically. In order to predict the thermal performance of the engineered system the thermal insult the test environment provides to a test unit must be quantified. To quantify the thermal insult, both temperature and heat flux measurements are necessary. However, as will be discussed, one of the major difficulties associated with conducting any type of fire test is making accurate measurements in both the fire and on the test unit. This paper discusses a number of measurement techniques. Due to the potential for errors in the measurements, the uncertainty in the measured parameters is emphasized.