The weighing procedure

• The right scale for the measurement:
  • Maximum capacity and precision
• Choosing the right container and lab tool for sampling
  • Sabot-spatula pairs, volumetric flask-pipette adapted to the physical state of the compound to be weighed.
• Prepare the scale: cleanliness of the plate, surroundings, level, and tare.
  • Use a brush to clean the scale and its environment: ensure the absence of contaminants that are likely to affect the measurement.
  • Check the horizontality of the scale with a spirit level
  • Make sure the scale is calibrated with calibration weights
  • Tare or record the exact mass of the container

• Sample small quantities of the product with a spatula or pipette until reaching the target quantity
  • Product safety code (might be necessary to work under a fume hood)
  • Solid or liquid sampling
  • Put the sample in the container
  • Record the exact mass (closed container in the case of volatile compounds)
  • Successive additions up to the desired mass

• Record the exact mass
  • The displayed value must be stable: the sliding windows of the scale must be closed. Take a precise reading of the displayed mass.