ISO 21885:2019 pdf download.Ships and marine technology一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 perating
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 stabilized
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.
5.5 Test procedures
5.5.1 General
The heated stairsteps specimen shall be tested using the test procedure specified in 5.5.2. However, the test procedure given in 5.5.3 shall be used when taking into consideration a special event or accident (e.g. blackout or low temperature operating procedures of anti-icing equipment as per the requirements agreed upon by the parties). See Figure 2.
5.5.2 Test procedure一Option 1
a) The test specimen shall be installed parallel to the wind flow inside the cold chamber. The stairsteps shall be tested with air flows above and below.
b) The test specimen shall be visually inspected and electrically and mechanically checked.
c) Good workmanship of the test specimen and conformity with the manufacturer’s drawings and
specifications can be assessed by visual inspection.
5.6 Pass/fail criteria
The stabilized value of the test-specimen temperature, excluding the lowest and highest values From 9 sample points,shall be constantly stable above 0 °C.
5.7 Test report
The test report shall include the following information:
a) test description:
— the name of the testing laboratory, the (late of the test, a unique test reference and report identification number;
b) the names of the sponsor/customer, the manufacturer;
c) a record of the test details:
— technical evidence of sample points, specimen temperature, ambient temperature, wind speed; ci) manufacture’s product clescnption:
— details of any component (as applicable) e.g.) material type, size, material thickness, heating element type, coating type,
— test specimen serial numbers (if applicable);ISO 21885 pdf download.