ISO 3468:2014 pdf free

ISO 3468:2014 pdf free.Passenger cars – Windscreen defrosting and demisting systems – Test method
Keep the vehicle, with the engine stopped, at the specified test temperature for a period of 10 h.This period can be shortened if instruments are available to check that the engine coolant, lubricant, and vehicle internal air have stabilized at the specified test temperature.
Measure the chamber temperature at the same height as the middle of the windscreen at a location, such that the temperature is not significantly affected by heat from the vehicle under test or by cold air entering the chamber.
Measure the horizontal component of the air velocity; cooling the chamber immediately prior to the test, at a point located on the longitudinal centreline of the vehicle, 300 mm ahead of the base of the windscreen, at a level half-way between the windscreen top and bottom. The velocity of this component shall be as low as possible and in any case less than 8 km/h.
After the period specified in 4.5.4 has elapsed, one or two observers can enter the vehicle; start the engine. An external power source can be used to start it but shall then be disconnected. The test period commences when the engine has been started and is running under its own power. Bring the defrosting system into operation as prescribed by the vehicle manufacturer, with the vehicle in the condition specified by the manufacturer for satisfactory operation at low temperature. The defroster blower can be turned on at any time.
For vehicles equipped with a conventional mechanical powertrain during the first 5 min of the test period, the engine speed can be adjusted according to manufacturer’s specification, recommended for warming up when starting in cold weather. For the remaining 35 min of the test, the engine shall be run at either
a) speed as indicated by the vehicle manufacturer, but in no case exceeding 50% of the speed at which it develops maximum power, or
b) if the vehicle manufacturer desires, on a chassis dynamometer, the engine speed and load shall not exceed the speed and equivalent road load at 40 km/h in the gear and with the tyre inflation pressures recommended by the vehicle manufacturer for the road load.ISO 3468 pdf free download.