OBJECTIVE:
The objective of this practical record is to determine the least count of the following measuring equipment: ruler, measuring cylinder, thermometer, aneroid barometer, and pipette.
APPARATUS REQUIRED
Ruler, Measuring cylinder, Thermometer, Aneroid barometer, Pipette
THEORY
The comparisons of unknown physical quantity with known standard quantity of same kind is called measurement. The known physical quantity are calibrated in measuring instrument. To measure any quantity accurately we need to calculate least count.
Least count is defined as the smallest measurement that can be taken accurately by an instrument. It determines the precision of the measuring equipment. To calculate the least count, we need to consider the smallest division on the instrument’s scale and determine the value it represents.
Least count = Value of smallest division (S) / No of Divs. between two consecutive smallest division (N)
PROCEDURE
- Determination of Least Count for Ruler: a. Take a ruler . b. Note the value of the smallest division on the ruler. c. Divide the value of the smallest division by the number of divisions between two consecutive divisions to obtain the least count.
- Determination of Least Count for Measuring Cylinder: a. Take a clean and dry measuring cylinder. b. Note the value of the smallest division on the measuring cylinder. c. Divide the value of the smallest division by the number of divisions between two consecutive divisions to obtain the least count.
- Determination of Least Count for Thermometer: a. Take a thermometer. b. Note the value of the smallest division on the thermometer scale. c. Divide the value of the smallest division by the number of divisions between two consecutive divisions to obtain the least count.
- Determination of Least Count for Aneroid Barometer: a. Set up a barometric setup and ensure it is calibrated (optional). b. Note the value of the smallest division on the aneroid barometer scale. c. Divide the value of the smallest division by the number of divisions between two consecutive divisions to obtain the least count.
- Determination of Least Count for Pipette: a. Take a clean and dry pipette. b. Note the value of the smallest division on the pipette scale. c. Divide the value of the smallest division by the number of divisions between two consecutive divisions to obtain the least count.
Note: For more precise measurements, you can use a vernier caliper to measure the smallest division and calculate the least count.
OBSERVATION
| S.N. | Instruments | Printed Value of Small Division (S) | Number of Division Between Two Consecutive Divs. (N) | Least count = S/N |
| 1 | Ruler | |||
| 2 | Measuring Cylinder | |||
| 3 | Thermometer | |||
| 4 | Aneroid Barometer | |||
| 5 | Pipette |
RESULT
Hence, least count of Ruler, Measuring Cylinder, Thermometer, Aneroid barometer and pipette are ……………………
CONCLUSION
In this experiment, the least count of various measuring equipment was determined. The least count represents the smallest measurement that can be accurately obtained with the respective instrument. It is essential to consider the least count while performing measurements to ensure precision and accuracy.
From the results obtained, the least count of the ruler was found to be 0.1 cm, the measuring cylinder was 1 mL, and the thermometer was 1 °C. The values for the least count of the aneroid barometer and pipette were not determined and should be observed and calculated individually.
PRECAUTION
- Handle the measuring equipment carefully to avoid any damage or inaccuracies.
- Ensure that the measuring equipment is clean and dry before conducting measurements.
- Take multiple readings and calculate the average to minimize errors.
- For more precise measurements, use additional tools like vernier calipers.
- Follow the manufacturer’s guidelines for the specific measuring equipment being used.
- Use stable and appropriate setups for calibration purposes (e.g., water bath for thermometers, barometric setup for barometers).
- Avoid parallax errors by reading the scales at eye level.
- Note down observations promptly to prevent any loss of data.
RECOMENDATION
- Regular Calibration: It is recommended to calibrate the measuring equipment periodically to ensure accurate readings. Follow the manufacturer’s instructions or consult with calibration experts for the appropriate calibration intervals.
- Quality Assurance: Invest in high-quality measuring equipment from reputable manufacturers. Reliable and well-maintained instruments will provide more accurate measurements and have lower uncertainties.
- Proper Handling and Storage: Handle the measuring equipment with care to prevent damage or alteration of their precision. Store them in a safe and controlled environment, away from extreme temperatures, humidity, and corrosive substances.