GB/T 23595.6-2009Test methods of rare earth yellow phosphor for white LED lamps - Part 6: Determination of conductivity (English PDF)

3.1 Deionized water

Conductivity <=2µS/cm.

3.2 Balance

Precision 0.001g.

3.3 Conductivity Meter

Measuring range 0µS/cm ~ 1000µS/cm, with temperature compensation, precision ± 0.2µS/cm.

3.4 plastic beaker

50mL.

3.5 magnetic stirrer

power <=90W, adjustable speed timing.

3.6 Magnetic sub

about 25mm.

3.7 Pipette

20mL.

4.1 Production Solution

4.1.1

Using an analytical balance (3.2) weigh the sample into 2g 50mL plastic beakers (3.4), and with a pipette (3.7) was added

20mL of deionized water (3.1), into a length of about 25mm magnetic sub (3.6), cover the slides.

4.1.2

The beaker containing the sample and water on a magnetic stirrer (3.5) After stirring 20min standing on stratification.

4.1.3

clear liquid upper layer was removed, was measured.

4.2 Test

4.2.1 Instrument Calibration

according to manufacturer's instructions prescribed method to calibrate the instrument.

4.2.2

Setting the cell constant and temperature compensation coefficient.

4.2.3

The temperature sensor and an electrode to be immersed in the sample with deionized water, shaking the liquid, read deionized water conductivity (deltaO) steady.

4.2.4

The temperature sensor and the electrode in the sample solution, shaking the liquid, when the display is stable, read the solution conductivity (deltaS).

5 Test results are expressed 5.1 conductivity of the sample solution (delta) according to equation (1).

delta = deltaS-deltaO (1)

Where.

deltaS --- conductivity of the solution, in units of µS/cm;

deltaO --- Deionized water conductivity, unit µS/cm.

5.2

Sample test three times in a row, the mean value. When delta<=20µS/cm, the poor value <=2µS/cm; when 20µS/cm < delta<= […]