Calibration of glassware under ISO 17025 by ANAB and SAC is an important process to ensure the accuracy of measurements and traceability to international standards. The important requirements and steps in glassware calibration are as follows:
ISO 17025 Requirements
ISO 17025 is an international standard for the technical competence of testing and calibration laboratories, including requirements for calibration of equipment and quality management. Calibration of glassware under ISO 17025 must take into account the traceability of measurements, temperature control and detailed data recording.
ANAB and SAC Requirements
ANAB (ANSI National Accreditation Board) and SAC (Singapore Accreditation Council) are the organizations that accredit laboratories according to ISO 17025. The requirements of ANAB and SAC focus on maintaining the technical competence and accuracy of measurements.
Glassware Calibration Procedures
Preparation and Cleaning
Ensure that all glassware is clean and dry to prevent contamination that may affect the measurement.
Temperature Control
Calibration must be performed at a controlled temperature, typically 20°C (68°F), as the volume of liquids can change with temperature.
Use of Distilled Water
Use distilled water as a calibration medium because it has a constant density.
Weight calibration
Make sure that the scale used to measure the mass of water is calibrated and accurate.
Calibration steps
Volumetric Flasks
1. Fill the flask to the calibration mark with distilled water.
2. Weigh the flask with water.
3. Subtract the weight of the empty flask to find the weight of water.
4. Calculate the volume using the density of water at the calibration temperature.
Pipettes and Burettes
1. Fill the pipette or burette with distilled water to the calibration mark.
2. Pour water into the weighed container.
3. Weigh the container with the water that has been released.
4. Calculate the volume using the mass of water and the density of water.
Measuring Cylinders
1. Fill the measuring cylinder to the desired mark with distilled water.
2. Pour water into the weighed container.
3. Weigh the container with water.
4. Calculate the volume using the mass and density of water.
Calculations
Density of Water Use the known density of water at the calibration temperature (e.g. 0.9982 g/mL at 20°C).
Recording and Adjustment
1. Record the data. Record the mass, calculated volume and deviation from expected volume.
2. Adjust, if necessary. Adjust the calibration mark according to the calculated volume to ensure accuracy.
Inspection and Certification
Regular Inspection. Regularly calibrate glassware to maintain accuracy and traceability.
Certification. Calibration must be certified by a recognized body, such as ANAB or SAC.
Calibration of glassware according to ISO 17025 requirements by ANAB and SAC certifies that laboratory measurements are accurate and conform to international standards.
