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BS ISO 7240-8:2014 pdf free

BS ISO 7240-8:2014 pdf free.Fire detection and alarm systems – Point-type fire detectors using a carbon monoxide sensor in combination with a heat sensor
If a test method requires a specimen to be operational, then the specimen shall be connected to suitable supply and monitoring equipment with characteristics as required by the manufacturer’s data.Unless otherwise specified in the test method, the supply parameters applied to the specimen shall be set within the manufacturer’s specified range(s) and shall remain substantially constant throughout the tests.The value chosen for each parameter shall normally be the nominal value, or the mean of the specified range. If a test procedure requires a specimen to be monitored to detect any alarm or fault signals, then connections shall be made to any necessary ancillary devices (e.g. through wiring to an end-of-line device for non-addressable detectors) to allow a fault signal to be recognized.
Install the specimen for which the CO response value is to be measured in a gas test chamber, as specified in Annex A, in its normal operating position, by its normal means of attachment. The orientation of the specimen, relative to the direction of gas flow, shall be the least sensitive orientation as determined in the directional dependence test (see 5.3), unless otherwise specified in the test procedure.
Raise the air temperature at a rate specified in the test and measure the heat response value as specified in ISO 7240-5:2012, 5.1.5 until the signal specified by the manufacturer is produced by the heat sensor.
NOTE If the detector is not capable of giving an alarm signal from heat alone, it will be necessary for the manufacturer to provide special means by which the heat response value can be measured. For example, it may be acceptable to provide a supplementary output that varies with temperature, or specially modified software to indicate when the air temperature has caused an internal temperature threshold to be reached. In such cases, the special means should preferably be chosen such that the nominal heat response value corresponds to a response time between the minimum and maximum times given in ISO 7240-5:2012, Table 4 for a class A2 detector. It is essential that the output signal be routed through the amplification path.BS ISO 7240-8 pdf download.

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