GB/T 5137.2-2020Test methods of safety glazing materials used on road vehicles - Part 2: Optical properties tests (English PDF)

5.1 Test purpose

Determine whether the safety glazing material has a certain regular transmittance.

5.2 Sample

It shall use the product or test piece. The test piece can be cut from the corresponding test area on the product. Before the test, the sample shall be clean and free of dirt and condensation.

5.4 Test procedure

5.4.1 TURN on the power of the instrument. Before putting the sample into the light path, adjust the display value of the receiver to 100. BLOCK the light path; adjust the receiver display value to 0.

5.4.2 PUT the sample between the diaphragms A1 and A2. Adjust the orientation of the sample, so that the incident angle of the beam and the glass surface is 90°±5°.

5.4.3 Determine the visible light transmittance of the sample; READ the receiver display value n. The result retains 1 decimal place. The visible light transmittance τr is equal to n/100.

6.1 Test purpose

Determine the angular separation between the primary and secondary images.

6.2 Sample

6.3 Test methods

Two test methods can be used:

6.4 Target test

6.4.1 Test apparatus

The test apparatus shall consist of the following parts:

a) Target-type illuminant control instrument: It is made of light box about 300 mm×300 mm×150 mm; with a target made of opaque black paper or matt black lacquered glass in front of it. Any one of Figure 2 can be chosen. The light box is illuminated with a suitable light source. The inner surface is coated with a matte white coating.

b) Sample holder: The sample can be placed at the real vehicle installation angle; and can be rotated and moved in the horizontal and vertical directions.

1 - Ring in the ring target;

2 - Ring in the spot-ring target;

3 - Center point of the spot-ring target;

D - For the ring target, it is the outer diameter of the ring; for the spot-ring target, it is the distance between the outer edge of the center point of the spot-ring target and the closest point inside the ring;

d - The difference between the outer diameter and the inner diameter of the ring, 2 mm.

In Figure 2, D is obtained from formula (1):

D - For the ring target, it is the outer diameter of the ring; for the spot-ring target, it is the distance between the outer edge of the center point of the spot-ring target and the closest point inside the ring; in millimeters (mm);

x - Distance between the sample and the target, in meters (m);

η - Limit of the separation of the secondary image, in minutes of arc (').

6.4.2 Test procedure

6.4.2.1 SET the sample according to Figure 3. SET the instrument in a dark room or dark place for observation. The distance between the sample and the target shall not be less than 7 m. 6.4.2. […]

6.5 Collimation telescope test

7.1 Test purpose

Determine the optical distortion of safety glazing material.

7.2 Sample

7.3 Test apparatus

The test apparatus shall consist of the following parts:

a) Slide projector: SELECT a suitable light source. The focal length shall not be less than 90 mm. The relative aperture shall be about 1/2.5. The light path is shown in Figure 7. A diaphragm with a diameter of 8 mm is placed about 10 mm in front of the lens.

b) Slide: The projected image is a bright circular array on a dark background.

The quality and contrast of the slide shall meet the test requirements, in order to control the measurement error within 5%. When the sample is not placed in the light path, the slide shall get the image shown in Figure 8 on the screen.

3 - Aperture, 8 mm in diameter;

D - The diameter of the circle projected on the screen, in millimeters (mm).

In Figure 8, D is obtained from formula (2):

R1 - The distance from the diaphragm of the slide projector to the sample, in millimeters (mm);

R2 - The distance from the sample to the screen, in millimeters (mm).

use only the central area of the projected image for measurement.

instrument so that the ratio R1/R2 is equal to 1.

c) Sample holder: The sample is placed at the real vehicle mounting angle and can rotate or move in the horizontal and vertical directions.

e) Checking template: Where a rapid assessment is required, the checking template shown in Figure 9 can be used to measure the change in spot size.

4 - Radius deviation between distorted image and undistorted image.

In Figure 9, A is obtained from formula (3):

ΔαL - Limit of optical distortion, in minutes of arc (');

R2 - Distance from the sample to the screen, in meters (m).

8.1 Test purpose

Determine the visible light reflectance of safety glazing material under standard illuminant A conditions.

8.3 Test apparatus

8.3.1 Test apparatus can be divided into spectrophotometer and photoelectric integrating photometer. The maximum allowable error shall not be greater than 1.5%. From the measured spectral reflectance value ρ(λ), the spectrophotometer shall be able to use the relative spectral power distribution function SA(λ) of the standard illuminant A and the CIE spectral luminous efficiency V(λ) to calculate the visible light reflectance for standard illuminant A. 8.3.3 The relative spectral power distribution of the light source of the photoelectric integrating photometer shall conform to the CIE standard illuminant A. The relative spectral response of the detector shall conform to the CIE spectral luminous efficiency V(λ); and directly generate the visible light reflectance of the standard illuminant A. a) Diffuse/vertical (d : 0°): The sample is diffusely illuminated by an integrating sphere. The angle between the normal of the sample and the axis of the measuring beam shall not exceed 10°. The angle between any one of the beams of at least one end of the receiving beam and its own optical axis does not exceed 5°. b) Vertical/diffuse (8° : d): The sample is illuminated by a beam of light. The angle between the axis of the beam and the normal of the sample shall not exceed 8°. USE an integrating sphere to collect the reflected luminous flux. The angle between any one of the beams of at least one end of the illuminating beam and its own optical axis does not exceed 5°. 8.3.5 The diameter of the integrating sphere of the test apparatus shall not be less than 100 mm. The total area of the opening shall not be greater than 10% of the surface area of the sphere. The inner surface of the sphere is uniformly coated with a highly diffuse reflective material, which is almost non-selective for the spectrum. 8.3. […]

8.4 Test procedure