Measuring cell voltage, which oscilloscope is good with wave generator combined

Thread Starter

RBelous

Joined Mar 28, 2021
8
Good day everyone,

New to the field.
I was wondering if you I could get an expert opinion and advice on my future experiment .

First phase of my experiment is to measure the voltage of set cells from different tissues.
1) Which Oscilloscope should I use to read voltage as slow as 0.07volts
2) How can we create, (sorry if using wrong term), anti-volt or negative volt.

3) as well what a good combo would you recommend for the wave generator as well

Thank you!
 

Reloadron

Joined Jan 15, 2015
5,876
You need to better define what you want to do? Voltage measurement is better done using a meter designed for it than a scope. Wave or Function Generator depends on what wave shapes and what amplitudes of wave shapes you want or need?

Ron
 

Thread Starter

RBelous

Joined Mar 28, 2021
8
You need to better define what you want to do? Voltage measurement is better done using a meter designed for it than a scope. Wave or Function Generator depends on what wave shapes and what amplitudes of wave shapes you want or need?

Ron
Thank you Ron.

Sorry for the confusion.
What exactly I am trying to do is to measure the voltage sample of a tissue. To see what voltage does a cell generates as different cells will produce different voltage under different stress environment. I guess similar to a circuit which will have a normal functional voltage of 3v. as an example but when there is a shortage or other, then voltage drops or other.

As for the wave generator. Looking at the low frequencies, basically if the tissue has abnormal voltage. to use generator to stimulate with the right wave bombardment.

Sorry if I am using wrong terms or not clear as I am new to this and learning as I go
 

Reloadron

Joined Jan 15, 2015
5,876
Sorry if I am using wrong terms or not clear as I am new to this and learning as I go
That's OK and we can work through things.

OK, so measuring voltage. This can get a little tricky. Based on what you mention a good bench type DMM (Digital Multi Meter) would likely be in order. Two concerns here are terms like resolution (the ability to read an instrument or of the instrument to be read and Uncertainty or Accuracy, how close to nominal does the instrument read. Never confuse the two. Good lab bench meters can be expensive and as features are added they get more expensive.

Wave shape generators are common and often called "Function Generator" things like wave shape (sine, triangle, sawtooth, square and pulse to name a few are important). Output power or amplitude are also important. Again, like a lab type voltmeter or multimeter a good signal generator can be costly. Good stuff is expensive so needs have to be established. Selecting the right TMDE (Test Measurement and Diagnostic Equipment) takes quite a bit of thought and work.

Ron
 

Thread Starter

RBelous

Joined Mar 28, 2021
8
That's OK and we can work through things.

OK, so measuring voltage. This can get a little tricky. Based on what you mention a good bench type DMM (Digital Multi Meter) would likely be in order. Two concerns here are terms like resolution (the ability to read an instrument or of the instrument to be read and Uncertainty or Accuracy, how close to nominal does the instrument read. Never confuse the two. Good lab bench meters can be expensive and as features are added they get more expensive.

Wave shape generators are common and often called "Function Generator" things like wave shape (sine, triangle, sawtooth, square and pulse to name a few are important). Output power or amplitude are also important. Again, like a lab type voltmeter or multimeter a good signal generator can be costly. Good stuff is expensive so needs have to be established. Selecting the right TMDE (Test Measurement and Diagnostic Equipment) takes quite a bit of thought and work.

Ron

Thank you Ron,

What do you think of this selection

1) For Oscilloscope, I am looking at the Siglent SDS1202x-200mhz
https://www.amazon.ca/Siglent-Techn...&qid=1616944899&sprefix=Rigol,aps,199&sr=8-15

2) Function generator, Signal Generator, JDS6600 60MHz

https://www.amazon.ca/Generator-Mul...id=1616945017&sprefix=functio,aps,185&sr=8-26

3) power supply, Kaiweets - used to create a test in controlled environment.

https://www.amazon.ca/KAIWEETS-Adju...616945212&sprefix=Rigol+power,aps,169&sr=8-10

Thank you for the help Ron!
 

Reloadron

Joined Jan 15, 2015
5,876
As long as the selected items meet your needs or requirements. Siglent is a new up and comer and they make real good stuff and a scope with an upper frequency limit of 200 MHz is plenty adequate for most applications. The function generator also looks good, I like the display. Again, as long as the output meets your needs. Power supply is hefty also. I do not see a good bench DMM for voltage measurement?

Ron
 

Thread Starter

RBelous

Joined Mar 28, 2021
8
Ron,

I do not see a good bench DMM for voltage measurement? - what would you recommend as I am still searching for one and oscilloscope only appears. I do see simple multimeter that used by electric but not sure if that would be sufficient
 

Reloadron

Joined Jan 15, 2015
5,876
Depends on your needs. I want to measure a DC voltage in the range of "something" and I need an accuracy or uncertainty of "something" with a budget of "something". See what I mean? Only you know the "something". :) Names like Fluke and Keithly come to mind. Keysight is high end. Rigol makes some good meters in a lower price range. Just as an example. I like the newer test equipment with USB and the old RS232 interfaces.

Ron
 

Thread Starter

RBelous

Joined Mar 28, 2021
8
Thank you Ron )
sorry I feel like a kid lost in a forest. A new project that trying to carry out with biological cells to measure their voltage current and learning as we go. Thank you so much for taking your time and sharing !

last question, then why we need oscilloscope if we can use the DMM instead to measure the cell membrane voltage current? Is there any benefits ?
 
Your biggest issue is a differential amplifier which rejects line frequency. We don;t know if the cells are attached to a human. Input impeadance that you need is a necessary. Electrometers have very high input Z and generally can measur very low current 1E-12 Amps or lower. A millivoltmeter is designed to measure low voltages.

Finally: Most AC meters are RMS reading, peak responding OR True RMS. What that means is, the RMS value is only valid for a sine wave within a particular crest factor and frequency range.

I had to do measurements using differential electrometers for resistivity and hall effect measurements on thin films.
 
Last edited:

Thread Starter

RBelous

Joined Mar 28, 2021
8
Your biggest issue is a differential amplifier which rejects line frequency. We don;t know if the cells are attached to a human. Input impeadance that you need is a necessary. Electrometers have very high input Z and generally can measur very low current 1E-12 Amps or lower. A millivoltmeter is designed to measure low voltages.

Finally: Most AC meters are RMS reading, peak responding OR True RMS. What that means is, the RMS value is only valid for a sine wave within a particular crest factor and frequency range.

I had to do measurements using differential electrometers for resistivity and hall effect measurements on thin films.

Thank you!
I am going to read on that more!
 
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