BS ISO 21885:2019 pdf download – Ships and marine technology – Testing specification for stairsteps using electrical resistance trace heating 5 Test method 5.1 Test purpose The purpose of the test is to evaluate whether or not the heated equipment is capable of preventing the formation of ice and can operate (function) properly when subjected to low temperature operating conditions. 5.2 Test facility requirements a) The test facility shall have the ability to maintain the specified temperature within the permissible range indicated in 5.3.2, in the available volume. b) The wind generated by the refrigerating machine installed inside the cold chamber shall not affect the specimen. c) A wind speed control system installed inside the cold chamber shall allow to generate a wind at constant speed. NOTE A test specimen installation method will be given with each equipment. 5.3 Test conditions 5.3.1 General The ambient temperature, wind speed, heating media and test-specimen temperature shall be recorded during the test. The test conditions shall be selected based upon the desired performance of the equipment. 5.3.2 Test temperature 5.3.2.1 General The equipment shall be tested at the temperatures agreed upon between the manufacturer and the purchaser. The test temperature shall be observed after the test-specimen temperature is stabiized according to 5.3.2.2. The temperature of the wind delivered to the test specimen shall be within +2。C of the test condition temperature during the steady state. Where, due to the size of the test chamber, it is not feasible to maintain these tolerances, the tolerances may be widened to +3。C down to -25 °C. A temperature sensor shall be installed between the wind generator and the test specimen to measure the ambient temperature. 5.3.2.2 Temperature stabilization a) Ambient temperature: once the ambient temperature does not change by +2 °C over a period of 30 min, it shall be considered as stabilized. 6) Specimen temperature: once the specimen temperature does not change by +2。C over a period of 60 min, it shall be considered as stabilized. 5.3.2.3 Temperature sensors a) Spatial resolution of temperature measurements shall be sufficient to identify cold spots on the surface of the test piece. No less than 9 sample points shall be used. b) Technical evidence shall be provided to identify the coldest spots to be used as sample points. c) The sample points need not be located within 50 mm of the perimeter, however, 5 sample points shall be...
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