Test Method Using Shield-cup for Evaluating Response Characteristics of Fire Detectors

Jang, Hyo-Yeon; Hwang, Cheol-Hong

doi:10.7731/kifse.8696ecf9

Cited by 3 publications

(3 citation statements)

References 20 publications

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“…Це обумовлено простотою реалізації та високою чутливістю таких сповіщувачів. В роботі [3] звертається увага на необхідність визначення оцінок основних характеристик пожежних сповіщувачів при їх випробуваннях. В цій же роботі, а також в [4] наводяться приклади випробувань пожежних сповіщувачів, за результатами яких одержані оцінки їх часу спрацювання.…”

Section: аналіз останніх досліджень і публікаційunclassified

Temperature Error When Determining the Time Parameter of a Fire Detector With a Thermoresistive Sensitive Element

Kozak

2021

MEC

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For fire detectors with a thermoresistive sensing element, a mathematical description of the reaction to the thermal action of an electric current pulse flowing through such a sensing element and having the shape of a right triangle is obtained. The mathematical description is constructed using the Laplace integral transformation and is shown to be a superposition of two Heaviside functions. The parameters of these functions are determined by the transmission coefficient and time constant of the thermoresistive sensitive element of the fire detector and the amplitude and duration of the electric current pulse. It is shown that the ratio of the output signals of the thermoresistive sensitive element of the fire detector at two a priori given moments of time can be used to determine the time parameter of the fire detector. The values of a priori set moments of time, in which the temperature of the thermoresistive sensitive element of the fire detector is determined, are selected under the condition of simplicity of technical implementation. If there is a change in ambient temperature, it leads to a temperature error as a function of the time parameter of the fire detector. For such an error, a mathematical description is obtained in the general case, as well as for the case when the thermal influence on the thermoresistive sensitive element of the fire detector is due to the flow of an electric current pulse in the form of a right triangle. It is shown that the value of the temperature error has a minimum at the values of the ratio of the output signals of the thermoresistive sensitive element of the fire detector at two a priori time points belonging to the range The value of this error does not exceed 4.9% with variations in ambient temperature, the value of which does not exceed 2.0%.

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Section: аналіз останніх досліджень і публікаційunclassified

Temperature Error When Determining the Time Parameter of a Fire Detector With a Thermoresistive Sensitive Element

Kozak

2021

MEC

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“…A promising option is a variant that provides for determining the technical condition of fire detectors. To this end, it is advisable to conduct their tests, the result of which should be to obtain assessments of their main characteristics [19]. Paper [19], as well as study [20], report the results of tests of fire detectors, during which estimates for one of their time parameters were obtained -the triggering time.…”

Section: Literature Review and Problem Statementmentioning

confidence: 99%

“…To this end, it is advisable to conduct their tests, the result of which should be to obtain assessments of their main characteristics [19]. Paper [19], as well as study [20], report the results of tests of fire detectors, during which estimates for one of their time parameters were obtained -the triggering time. In [21], the results of obtaining estimates of the actuation time and the actuation time index (RTI) for thermal fire detectors of the maximum type are given.…”

Section: Literature Review and Problem Statementmentioning

confidence: 99%

Substantiating the pulse method for determining the time parameter of fire detectors with a thermoresistive sensing element

Abramov

Basmanov

Kozak

2021

EEJET

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This paper substantiates the pulse method for determining the time parameter for fire detectors with a thermoresistive sensing element ‒ the time constant. The method is based on using the Joule-Lenz effect, which manifests itself when an electric current pulse passes through the thermoresistive sensing element of fire detectors. Thermal processes in such a sensing element are described by a mathematical model that belongs to the class of equations of mathematical physics. The solution to the differential equation of this class was derived using the Hankel integral transformation and is represented as a series relative to the Bessel functions. The resulting solution is used to construct a mathematical model of a thermoresistive sensing element in the form of a transfer function, which takes the form of the transfer function of the inertial link. To trigger the thermoresistive sensing element of fire detectors, a single pulse of electric current in the shape of a rectangular triangle is used. The integral Laplace transformation was applied to mathematically describe the response of a thermoresistive sensing element to the thermal effect of such a test influence. To obtain information about the time parameter of fire detectors with a thermoresistive sensing element, the ratio of its output signals is used, which are measured in the a priori defined moments. A two-parametric expression was built to determine the time parameter of fire detectors; a verbal interpretation of the pulse method to determine it was provided. The implementation of this method ensures the invariance of the time parameter of fire detectors with a thermoresistive sensing element relative to the amplitude of a single pulse of an electric current, as well as relative to the parameter that is included in its transfer coefficient.

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Experimental testing and evaluation of coating on cables in container fire test facility

Aurtherson¹,

Hemanandh

Devarajan

et al. 2022

Nuclear Engineering and Technology

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Test Method Using Shield-cup for Evaluating Response Characteristics of Fire Detectors

Cited by 3 publications

References 20 publications

Temperature Error When Determining the Time Parameter of a Fire Detector With a Thermoresistive Sensitive Element

Temperature Error When Determining the Time Parameter of a Fire Detector With a Thermoresistive Sensitive Element

Substantiating the pulse method for determining the time parameter of fire detectors with a thermoresistive sensing element

Experimental testing and evaluation of coating on cables in container fire test facility

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