ISO 3468 pdf download Passenger cars — Windscreen defrosting and demisting systems — Test method
ThisInternationalStandardspecifies thetestmethodfor passengercar (IS0 3833:1977,3.1.1) windscreendefrosting and demisting systems, when these are fitted.
This International Standard does not specify reference areas or levels of performance
The test condition of-18 C + 3 °C specified for defrosting systems will meet the majority of cold climaticrequirements.
The tests for demisting systems are conducted at a temperature of -3°C + 1C, since this is the practicaminimum temperature at which mist, as defined in 3.7, can normally occur.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and areindispensable for its application. For dated references, only the edition cited applies. For undatedreferences, the latest edition of the referenced document (including any amendments) applies.
ISO 1176:1990, Road vehicles – Masses – Vocabulary and codesISO 3833:1977, Road vehicles — Types – Terms and definitionsISO 6549:1980, Road vehicles – Procedure for H-point determination1)
3Terms and definitions
For the purposes of this document, the following definitions apply.
3.1defrosted areaarea of the outer glazed surface of the windscreen having a dry surface or covered with melted orpartially melted (wet) frost, excluding any area of the windscreen covered with dry frost
defrostingelimination of frost and/or ice covering the outer glazed surface of the windscreen by the operation ofthe windscreen defrosting and/or windscreen wiping and washing systems
3.3windscreen defrosting systemdevice,or combination of devices,intended by the vehicle manufacturer to eliminate frost or ice from theglazed surfaces of the windscreen and thus restore visibility, together with the necessary accessoriesand controls
windscreen wiping system
device for wiping the windscreen outer glazed surface, together with the necessary accessories and
windscreen washing systemdevice for storing washer solution and applying it to the windscreen outer glazed surface together withthe necessary controls
road loadpower output, as indicated by the vehicle manufacturer, required to move the vehicle on a flat road at aspecified speed through still air at 20 C, with a standard barometric pressure of 1 013 mbar; the massofthe vehicle being equal to the complete vehicle kerb mass,in accordance with ISO 1176 (ISO-M06) plus150 kg, i.e. representing the driver and passenger on the front seats
Note 1 to entry: Road load takes account oftransmission friction, rolling friction, and air resistance.
mistfilm of condensate on interior glazed surface
demistingelimination of mist from the windscreen by the operation ofthe windscreen demisting system
windscreen demisting system
device, or combination of devices, intended by the vehicle manufacturer to remove mist from thewindscreen and thus restore visibility together with the necessary accessories and controls
4 Test method for defrosting systems
4.1 Performance requirements
When testedin accordance with the followingprocedure,and atthe temperature specified,the defrostingsystem shall be capable of defrosting specified percentages of specified areas after stated time intervalsfrom the start of the test.