1.0 Introduction
1.1 Background Information and Definition
In the laboratory, many apparatus are being used these equipments are normally calibrated at a standard temperature recommended by the national standard of weights of the particular country of the manufacturer. In America, national bureau of standard institution (NBSI) is been used. For every accurate work, it may be necessary to recalibrate a particular piece of apparatus in the laboratory. For this purpose, it is desirable to recalibrate a (250ml) volumetric flask, to measure the exact volumes delivered or contained (MCGRAW Hill 1971).
Calibration is defined as a quantitative measurement of the instrument undertaken to ensure accurate performance confirmation. It generally involves adjusting the values of internal components so that the indication is correct at a specific number of points on the indicating scale and approximately correct between these points.
Volumetric flask is glassware that points in the laboratory for analytical experiment. It is used to prepare a solution of a known volume. It is calibrated to contain a particular volume of water (distilled water) at 20oC, when the bottom of the meniscus is adjusted to the center of the line marked of the neck of the flask. Most flack bears the label TC 20oC, which means that the flask is calibrated to contain the indicated volume at 20oC temperature range.
1.2 Statement of Problem
Many laboratory instruments exhibit drift, a show charge in output. Environmental factor such as temperature also affects the performance of certain instruments in the laboratory. The instrument maker must choose materials and operating principles, which will minimize this effect and the user must develop measurement techniques (e.g. recalibration) which either avoid these effects or correct for them.
1.3 Aim and Objectives of the Study
The aim of the study is to recalibrate 250ml volumetric flask that can be used to prepare a solution of known volume. In achieving this aim, the following specific objectives were laid out as follows:
- To give a sound understanding of modern measurement methods and knowledge of equipment used.
- To experiment, promote and improve techniques in handling of volumetric flak.
1.4 Hypothesis
In order to pursue the objective of this study, the following generalized statements have been designed to guide and aids in obtaining the result for the experiment to be conducted.
- In regard to the accuracy of an instrument, it should be noted that no instrument is accurate in an absolute sense.
- Every instrument (devices) gives only a more or less close approximation to the standard value.
- Recalibration is carried out for reliability and accurate scientific work.
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