I predicted even before the EE day that there will be a lot of different problems arise from my EE experiment. And that’s exactly what happened today. First of all, my original method involves using a burette. However, it’s really difficult to measure the temperature of the water drops exactly. Since it’s a long narrow tube, it’s difficult to assume that the water on the top of the burette has the same temperature as the water dripping out of the burette. Then, after taking some tour to the different science department, I was casually introduced to using a shorter-length and bigger-width syringe instead. And I realise that it can solve my problems better. Now, the liquid can be mixed together equally, the top can be closed by a stopper, and the syringe can be wrapped around with aluminium foil to reduce heat loss. Hence, one problem solved.
Then, I decided to do a preliminary trial to find the correction factor “f” as well as finding the surface tension of water at other different temperature instead of the room temperature. I used a “water drop counter” in this experiment, it will tell me precisely the volume of each water drop. However, there is a bit of a technical problem, since I’ve never used this kind of equipment before. Due to time constraint and trust issues, I decided to try to do the experiment manually. However, after I get the value for the surface tension of water at 60 Celsius and compare it to the literature value, I realise that the value I found is close to the real value but it’s also close to the other surface tension values of the other temperature (e.g. it’s also close to the value of the water at 40 Celsius), too. The error bar is too big that it overlaps with the value of the other independent variable.
Then, I realise that I shall change my equipment to more precision ones. That’s when I decided to measure the volume of the water drops using a precision mass balance to 3 decimal places and count the water drops to 50 instead. Then, I set up the whole experiment at the back of the science class so to prepare for the next time I came, so that I just have to conduct the experiment and record the results directly.