(1) The first task was establishing a bench-scale test that would assign a detector
response sensitivity index for each fixed temperature heat detector. The theory
behind the test, as well as a method for practical implementation of the theory,
was developed by utilizing the plunge-tunnel [2], which has been used to assign
response time index (RTI) of automatic sprinklers. The RTI principles were first
applied to predicting response of heat detectors by Heskestad and Delichatsios
[3] in the late 1970s. Following the same principles, Bissell [4] measured the RTI
values of several heat detectors in the late 1980s. However, somehow these early
contributions had not been fully materialized and the RTI values in heat
detectors have not been adopted yet as a part of industry standards.