I would go for something that matches the particular industry you want to get in with. Employers will nearly always ask you what your final year project was about. If you have experience with a process or the same type of instrumentation that they use then it will be very encouraging to them...
Ok I will try and break it down what I want to achieve. I would be grateful if you could verify if this methodology is valid.
I thought about FFT'in the data, but the customer requires that the resistive divider measurement system permit measurements of better than 0.2ppm of PS noise. The...
The equipment is a mass spectrometer (MS) and is considered “supply critical”, that is the quality of the results that it outputs will be directly related to the noise of the power supply. So it is no good me quoting to the customer that the HV power supply has a RMS noise of X Vrms when it is...
Sorry I posted this without reading your last comment. But does what I said above^ make sense ? I will try and get my head around what you just said...please bare with my "slowness" in this subject area.
So when I am evaluating to see if my DVM can permit measurements of my desired resolution at 0.5Hz I need to look over the entire 2 second interval (1/0.5) and say "If a noise signal of 0.5Hz or GREATER occurs in the 2 second interval AND the peak-to-peak voltage is greater than what my system...
Hi vk6kro as I said I no longer have access to this DVM or resistive divider, the results I collected are from a while ago. I understand what you are saying with the integration process, but there is nothing I can do to change that. I had to set the NPLC to 4 in order to get rid of 50 hz (UK)...
I cannot use any filter the results that I have were collected a while again and I no longer have access to the DVM or the resistive divider
I have done this before. Unfortunately I cannot find the result but I remember conducting 2 tests; both tests involved connecting a 50Hz signal...
Yeah I read somewhere that it takes a human about 1/10 of a second to react to a stimulus, not sure if this applies to being able to distinguish between stimulus.
I will leave it until you get some time to cast your eye on my excel pic that I posted, hopefully it will clear things up.
I have a specification that I must adhere to. That is my measurement system (resistive divider) must be quiet enough to enable sub-ppm measurements of a HV power supply...
Just took a very quick look. I think if you were to make the signal smoother then you are effectively attenuating the AC content of the signal, so if you were to increase the cap size then the audio would become quieter.
If you wanted to improve the audio quality replace the cap with a...
Yes you can get electronic Delay On Timer relays these are readily available from rswww. If you go down that route then there is no need for capacitors or resistors like I drew.
Here is something similar to what you need:
http://www.ics-timers.com/op4142_2.html
Hi sophiecentaur, it seems like you always come to my rescue lol.
I can't get my head around why I need a filter before my sampling circuit.
My DVM has a cut off frequency of 12.5Hz (it samples every 0.08 seconds).
I don't think Nyquist principles apply here because my excel equation...
You'd have to calculate your RC time constants yourself. The switch is a 3 pole 2 throw switch readily available for cheap off RS. You have to wire up the "main pole" up NO and the other 2 poles need to be NC, this will discharge the caps ready for the next time you operate the "main pole".
I think it depends on the DVM you are using and how many readings you taking. I know with the agielent 3458A if you take over 5000 readings they get stored inside the DVM memory before you can suck them back out.