SJ/Z 11388-2009General guidelines of environment-friendly use period of electronic information products (English PDF)

5.1 Instruments and utensils

5.1.1 Balance: Sensitivity 0.1, 0.01 g.

5.1.2 Electric screening machine.

5.1.3 Round-hole selection sieve: Sieve diameter 1.0, 1.2, 2.0, 3.0 mm; with

sieve bottom and sieve cover.

5.1.4 Sample trays, small dishes, scalpels, magnifying lens, tweezers, brushes, etc.

5.2 Screening

Put the required sieves on the bottom of the sieve in the order of aperture from small to large; pour an appropriate amount of specimen into the center of the top sieve; cover the sieve.

5.2.1 Hand screen

Place the round-hole screen on a glass plate or a smooth table. Use both hands to screen clockwise and counterclockwise for 1 min at a speed of (110 ~ 120) times/min. The screen amplitude is the screening diameter plus (8 ~ 10) cm expanded diameter.

5.2.2 Machine screen

Use an electric screening machine to rotate at a speed of (110 ~ 120) times/min, with 1/2 of the screening radius as the screen amplitude; perform screening for

2 min.

5.3 Large sample impurity inspection

5.3.1 Operation method

Prepare an average sample according to Chapter 4. According to the categories of large, medium, small oil bearing materials, use a sample divider or quartering method to take samples for bulk impurity inspection. The sample size is as shown in Appendix A (Normative). Weigh it on a balance which has a sensitivity of 0.1 g. According to the categories of the oil bearing materials, pour it into the specified round-hole screen in several times (not exceeding 250 g each time).

See Appendix B (Normative) for the selection of screen specifications. Perform screening according to 5.2. After the screening, gently remove the screen; pour the material above the screen into the sample pan. Merge the stuff in the sieve hole into the sample above the screen. Pour out the material below the screen from the bottom pan. Use a brush to clean the dust which attaches to the bottom pan. Include it into the material below the screen. Use tweezers to pick out large impurities. Combine them with the material below the screen. Weigh them on a balance which has a sensitivity of 0.01 g.

5.3.2 Calculation of results

Calculate the percentage of impurities in the large-sized sample according to

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