In a RoHS 2.0 laboratory, physicochemical equipment is often used to test the content of four or seven phthalates. During the sample pretreatment stage, an electronic balance is used to accurately weigh the samples. For example, when detecting phthalates in plastic toys, accurately weighing the toy sample is the basis for obtaining reliable results.

Before using the analytical balance to weigh samples, preheat the balance and check whether it is in a horizontal position. Observe whether the bubble is in the center position. If so, it indicates that the balance is in a balanced position; otherwise, adjust the anchor bolts clockwise or counterclockwise to center the bubble.

Press the tare key. After the value returns to zero, press the calibration key. When "CRL - 100" flashes, place a 100g weight on the weighing pan.

When the display value stabilizes at 100.0000g, remove the weight. After zeroing, place a 100g weight again for verification.

After the calibration is completed, the test sample can be weighed and pretreated for extraction.

When weighing, open the glass door, place the weighing container (weighing paper, small beaker, etc.) on the weighing pan, and then close the glass door.

After the reading stabilizes, press the "tare/zero" key. After the balance reading returns to zero, open the glass door and place the sample for weighing.

Gently place the sample to be weighed on the weighing container. After the balance value stabilizes, record the value, which is the weight of the sample.

After weighing, promptly remove the container on the weighing pan and wipe the weighing pan to keep it clean.