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    Activity #4: Name: Section/Group: Subject: Analytical Chemistry Lab Bachelor in Medical Laboratory Science

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    Dan Christian Blance
    This document describes an experiment to calibrate pipettes by determining their accuracy and precision in delivering nominal volumes. Students weigh water dispensed from a serological pipette to calculate the actual volume delivered. They repeat this process at least 10 times, average the results, and use the density of water to calculate volume from mass. Comparing the calculated volume to the nominal setting allows students to determine the pipette's accuracy and ensure it is properly calibrated within 99-101%. Calibration is important for accurate measurements and sources of error must be minimized.

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    Activity #4: Name: Section/Group: Subject: Analytical Chemistry Lab Bachelor in Medical Laboratory Science

    Uploaded by

    Dan Christian Blance
    21 views3 pages
    This document describes an experiment to calibrate pipettes by determining their accuracy and precision in delivering nominal volumes. Students weigh water dispensed from a serological pipette to calculate the actual volume delivered. They repeat this process at least 10 times, average the results, and use the density of water to calculate volume from mass. Comparing the calculated volume to the nominal setting allows students to determine the pipette's accuracy and ensure it is properly calibrated within 99-101%. Calibration is important for accurate measurements and sources of error must be minimized.

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    This document describes an experiment to calibrate pipettes by determining their accuracy and precision in delivering nominal volumes. Students weigh water dispensed from a serological pipette to calculate the actual volume delivered. They repeat this process at least 10 times, average the results, and use the density of water to calculate volume from mass. Comparing the calculated volume to the nominal setting allows students to determine the pipette's accuracy and ensure it is properly calibrated within 99-101%. Calibration is important for accurate measurements and sources of error must be minimized.

    Copyright:

    © All Rights Reserved
    Download as DOCX, PDF, TXT or read online from Scribd
    Download as docx, pdf, or txt
    21 views3 pages

    Activity #4: Name: Section/Group: Subject: Analytical Chemistry Lab Bachelor in Medical Laboratory Science

    Uploaded by

    Dan Christian Blance
    This document describes an experiment to calibrate pipettes by determining their accuracy and precision in delivering nominal volumes. Students weigh water dispensed from a serological pipette to calculate the actual volume delivered. They repeat this process at least 10 times, average the results, and use the density of water to calculate volume from mass. Comparing the calculated volume to the nominal setting allows students to determine the pipette's accuracy and ensure it is properly calibrated within 99-101%. Calibration is important for accurate measurements and sources of error must be minimized.

    Copyright:

    © All Rights Reserved
    Download as DOCX, PDF, TXT or read online from Scribd
    Download as docx, pdf, or txt
    of 3

    Name:

    Section/Group:
    Subject: ANALYTICAL CHEMISTRY LAB
    BACHELOR IN MEDICAL LABORATORY SCIENCE

    ACTIVITY #4

    DATE ACTIVITY NAME: PREPARED BY SCORE:


    i CM
    Calibration of Pipettes Nigell Mikhail A. Gallardo, RMT, MLS (ASCP )

    INTRODUCTION

    An ordinary laboratory pipette may be expected to deliver its nominal volume with good precision and
    good accuracy if it is used in the way recommended. In this experiment, we investigate the precision and
    accuracy of such pipette by making accurate determinations of the mass of waters it delivers in repeated
    operations.

    OBJECTIVES

    UPON COMPLETION OF THIS ACTIVITY, THE STUDENT SHOULD BE ABLE:


    1. To be able to know the importance of Calibration
    2. To determine the accuracy of the reading instrument.
    3. To correctly select and read the appropriate volume for dispensing and to accurately determine the mass of water.

    MATERIALS/CHEMICALS NEEDED

    BEAKER
    DISTILLED WATER
    SEROLOGICAL PIPETTE
    ASPIRATOR
    ANALYTICAL BALANCE
    ERLENMEYER FLASK
    THERMOMETER

    PROCEDURE
    1. Prepare all materials needed.
    2. Obtained distilled water in the Erlenmeyer flask and let it stand on the bench for about 15 minutes before determining its
    temperature.
    3. Weigh the beaker using the analytical balance.
    4. Measure 10ml of distilled water using the serological pipette into the beaker, and determine the mass of water discharged by
    taking the difference.
    5. Repeat this process to take at least 10 readings.

    CALCULATIONS:

    a) Define the formula for calculated volume:


     The formula for calculating the volume dispensed by the pipette is V = w * Z where w is the weight of
    the water, Z is the conversion factor based on the density of the water, and V is the calculated volume
    of how much water was dispensed.
    b) Average the replicates together. You should have weighed the volume of water dispensed by the pipette at
    least 10 times. In order to average all of these values together, add them all up and divide by 10.
    c) Plug the variables into the equation and solve. Once you have determined the proper numbers to use for each
    variable, you can plug them into the equation and solve for the calculated volume. To solve, multiply the
    average weight of all the trials by Z value.
    d) Calculate the accuracy of the pipette. To calculate the accuracy, you can use the equation:
    A = 100 Vavg / V0 is the value you set the pipette to dispense. Accuracy should be between 99-101%. If the
    pipette is properly calibrated, the calculated value should be very close to the actual value you set on the
    pipette.

    QUESTIONS FOR RESEARCH

    1. Illustrate the procedure of pipette calibration


    2. What is the importance of calibration? How can you

    Page 2
    3. Give and describe examples of sources of error in calibration.

    Page 3

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