experiment

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labReports.pdf
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For the experiment to be repeated from the details it is necessary to give a detailed record of any important conditions of the experiment (operating temperatur., pressures …etc), any specific techniquet that were used (equipment calibration … etc) and any materials involved (10M hydrochloric acid, cast iron …etc). It is critical to include all relevant information but to ensure the report is sufficiently concise exclude extraneous detail. For .ample, if a voltmeter is used during the experiment to record the potential difference produced by the solar cell in the above example, it may be useful to record the manufacture and model number, the precision of the instrument, the zero-offset and any calibration that was performed. A record of a the colour of the voltmeter will be of no consequence to to results and should not be included in the lab report. The section where the method of the experiment is described is a convenient location to discuss any safety precautions or procedurco that were observed or any PPE (personal protective equipment) that was used. In summary, the body of the report should include the method, materials and equipment used during the work. The most important aspect is to be thorough and include all relevant detail while being accurate, concise and avoiding irrelevant information and waffle.
2.6.1 A note about accuracy and precision While to two terms are often confused in scientific reports, accuracy and precision have exact and different definitions. • accuracy – the quality of being near to the true value • precision – the quality of being reproducible in amount or performance 1 If a voltmeter reads to 0.00001 volts then it is a very precise instrument. However, if the reading it totally wrong, then it would still be very precise but would not be particularity accurate. For .ample, lets say that a serim of voltmeters are reading a potential difference of 12.34567 volts.
• Voltmeter 1 reads 12.3 volts – this is accurate but not very precise • Voltmeter 2 reads 1.31279 volts – this is precise but not very accurate • Voltmeter 3 reads 1.3 volts – this is neither accurate nor precise • Voltmeter 4 reads 12.34567 volts – this is accurate and precise
2.7 Results The results section of a lab report contains a description of the data that was collected during the experiment or investigationhat is being documented. Should any numerical processing be necessary on the raw data collected from the experiment this should should be performed outside the report. For example, if measurement are taken in millimetres from a manometer, the results presented should be converted into appropriate units of pressure. A brief d.cription should of how the processing was conducted should be included in the body of the report of in the results section, but details are not necessary. For example, a statement such as “the measurement from the u-tube manometer were converted to SI units using the manufacturm conversion tables”. If inclusion of further details of the numerical processing or raw data is justified but not appropriate for the results section, they may be included in an appendix. In addition to the measurements taken during the .periment, the results section should include any observations that were made during the experiment. Unexpected phenomena may
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affect the results in ways that are not know by the author of the lab report but may be of significance to the reader. For example, if work is conducted on a water flow system and a large number of bubbles is observed in the supply or there is a large oscillation in the values reported from measurement equipment, record it in the results section. A well writing results section of a lab report highlights the trends associated with the work being conducted rather than giving details of .act results. In the introduction section an aim, hypothesis or reason for conducting the experiment should have been proposed. The data presented in the results section should demonstrate how these objectives have been met. For example, if the aim of an experiment was to optimize the level of fuel consumption in a petrol can by varying travelling speed, then the results section should show a plot of miles per gallon against miles per hour. The details of the amount of fuel used, distance travelled by the car, the variation of length of journey, the elimination of results from acceleration and deceleration and other processing techniqu. should only be briefly described.