SAE J902 pdf download
SAE J902 pdf download.Passenger Car Windshield Defrosting Systems.
1. This SAE Recommended Practice provides a test procedure and performance guideline for evaluating passenger vehicle windshield defrosting systems. It is limited to results of tests that can be conducted on uniform test equipment in commercially available laboratory facilities.
The current engineering practice prescribes that for laboratory evaluation of defroster systems, a known quantity of water shall be sprayed on the windshield to form an Ice coatwg and then melted by the defroster under specific vehicle operating conditions. The procedure provides uniform and repeatable laboratory test results, even though under actual conditions such a coating would be removed by scraping before driving the vehicle. The performance obtained, therefore, does not directly relate to actual driving conditions, but serves as a laboratory performance indicator for comparing test results within or between systems.
This document is intended as a guide toward standard practice but may be subject to frequent change to keep pace with experience and technical advances and this should be kept in mind when considering its use.
2. References
2.1 ApplIcable Publications—The following publications form a part of this specification to the extent specified herein. Unless otherwise indicated, the latest issue of SAE publications shall apply.
2.1.1 SAE Puai.IcAToNs—Available from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001.
SAE J826—Devices for Use in Defining and Measuring Vehicle Seating Accommodation
SAE J903c—Passenger Vehicle Windshield Wiper Systems
SAE J941—Mo(or Vehicle Driver’s Eye Location
SAE Ji 100—Motor Vehicle Dimensions
2.2 Related Publications—The following publications are provided for information purposes only and are not a required part of this document.
2.2.1 ISO PuBUCATiON—Available from ANSI, 25 West 43rd Street. New York. NY 10036-8002,
ISO 3468—Road vehicles—Windscreen defrosting systems for passenger cars—Test methods
4.1 Area to be Defrosted—The minimum windshield area that shall be defrosted is described by the use of two specified areas identified in Table 1 as areas A and C. Each area has been established using the angles of Table I applied as shown in Figures 1 and 2. In Figure 1. the upper and lower boundar,es of the area are established by the intersection of two planes, tangent to the upper and lower sides of the eye range contour. with the windshield glazing surface. The planes are fixed by angles above and below the glazing surface reference line. In Figure 2, the left and right boundaries of the area are established by the intersection ot two planes tangent to the left and right sides ot the eye range contour. The planes are fixed by angles to the left and right of the plan view reference line. Using the test procedures established in 4.4, a minimum of 80% of area A and 100% of area C should be defrosted in 30 mm. The areas used in determining the percentage of defrosted area are those areas on the exterior glazing surface which are not withIn 25.4 mm of the edge of the daylight opening (plllar, division bar, header, etc.). Figure 3 illustrates all of the areas on a typical windshield. The percentage is the ratio of the defrosted area within the defined area to the defined area.
4.2 Test Conditions
4.2.1 SOAK TMPERATURE—18 C maximum C (0 F maximum)
4.2.2 ENGINE LOAD AND SPEED.—(TO COTAIN NORMAL OPERATiNG TEMPERATURES)
4.2.2,1 Vehicle shall be operated either with engine RPM not to exceed 1500 rpm + 50 rpm in neutral gear, or any speed not to exceed the 40 kmlh (25 mph) at road load condihon in the manufacturer’s recommended gear.
4.2,2,2 For Electric Vehicles (or Other Vehicles with Electric Windshield)Test to be run in park with any electric drive motor ott. The battery system should be at full charge prior to test.
4.2.23 For Hybrid Electric VehiclesThe test should be run per 4.2.2.1 with the powertrain control logic per manufacturers specification at —18 °C. The battery system should be at full charge prior to test.
4.2.2,4 For vehicles with remote start installed by the OEM, the test should not be run using this feature.
4.2.2.5 The chassas dynamorneter load used to simulate road load shall be calculated as follows:
Using the product of the overall width (W117) and overall height (HIOl), as defined by SAE
approximate the vehicle cross-sectional area, determine the vehicle air resistance horsepower using Equation 1.
