The Logbook In a professional context, the time and effort devoted to an experiment can only be justified if results are properly recorded: carefully, accurately, and unambiguously, so that on a later occasion, sometimes much later, a report may be prepared for someone else to read – perhaps a superior, or for publication. You may find the way of "writing up" an experiment hard to understand, and to adjust to, but academia and industry set a high priority on it. Thus, it is very important to maintain a clear and careful observation of experiments in the form of notes, datasets, and screenshots. The place for your observations is your logbook, to record what happens as you do it. It is your own record and for teaching and evaluation purposes as it is being assessed from time to time. The main issue which cannot be overstated is the full and accurate recording of the facts and observations of your experimental work. Therefore, we insist that all recording of observations is made directly into the logbook. Many students have difficulty in avoiding the tendency to treat the logbook as a formal document. Therefore, the following rules and observations should be noted: Carefully constructed sentences, carefully underlined headings etc. might not be a good practice since it may incur in a waste of lab time. Do not use loose sheets of paper for intermediate recording before transfer to the logbook - this obviates the point of the logbook and is not allowed. The Logbook - general At the beginning, number the pages throughout the book and as work proceeds keep an-up-to date contents list at the front. The Heading The record for each attendance in the lab must be headed with a few standard items of information, i.e., your group member name, the title of the experiment, and the date. The Date Dating is a point which is to be particularly stressed, as its significance seems not to be generally appreciated. Experience tells that there are many reasons for dating every observation: it enables you to check the order in which observations were made, to check consistency of your records, to establish priority on major discoveries, such as establishing your claim to a patent or copyright. The key is remembering to do it at the time of experiment. This is one of the habits that we aim to develop, and it is important enough to be considered in assessing credit. The Text Judging what and how much to write is a skill to be developed in these labs. Text should be concise but note down enough while being in the lab to serve as an adequate reminder, otherwise the work and the time spent writing it up are wasted. On some occasions, it will provide the basis for a formal report. When you are recording observations, make it quite clear that this is what you actually did or observed. There must be no room for confusion with what you were intended to do, expected, calculated, or even what one usually does. This is one of the common weaknesses. The typical observation is a set of values of variables €h occur in a given system under given test conditions, for example the current that arises in a circuit when there is a given input voltage and temperature. Therefore, all details relevant to the test conditions must be recorded for each set of readings for which they apply - e.g. signal amplitude, frequency, what instruments connected, etc. - The log is not a formal document. Whilst appearance is secondary to the content, your writing must be legible to others – not just yourself. What matters above all is that you can trust it as a true and intelligible record. This is not only relevant for other readers, but for your own reference. Ideas and facts may seem clear at the time of undertaking the work, but they rapidly become confused and in a few months' time you may not be able to understand your own notes, or there may be vital facts missing. At least read what you have written at the time to see if it makes sense. Write text on the ruled pages only: text written on the graph side is much harder to read and may confuse the reader. Do not use correcting fluids such as Tippex. It is time-wasting, has poorer appearance than neat scoring-through, and shows lack of confidence. It is also recommended that you preserve rejected work as it could later have some value, or even turn out to be correct! The account of every experiment should end with a statement of conclusions and demonstrate understanding which you have been able to draw from it. Diagrams Diagrams such as circuits may be drawn on either ruled or graph pages. Do not copy out complex diagrams into logbooks, but refer to them freely, as if they are at hand. Copying out can give a sense of doing something useful, but this is false; it is a pure waste of lab time. When referring to diagrams in the text always make it quite clear which one. In order to refer to points in a circuit diagram it is useful to adopt a scheme of labelling, rather than long-winded descriptions; thus, each point involved may be marked with a letter. Make use of simplified versions of diagrams if appropriate. Oscilloscope traces Very often you will need to record waveforms from the scope screen; the guidelines below should be followed: • Use a pencil for sketching graphs to allow ease of correction. • Do not sketch more than one cycle of a repetitive signal unless it is essential to the purpose of the exercise. You must state whether the Y amplifier was DC coupled and if so, show the 0-volt level on the sketch. • You must show the axes scales and indicate whether a 10:1 probe was used. • State fully the test conditions./n