I am looking for an oscilloscope capable of displaying voltage signal in the range 0.1mV to 1mV, timescale around 0.1s to 2s. I am unclear from the product description whether the HPS50 or HPS140i are able to display a signal in this range. Sensitivity is given as 0.1mV, but the minimum voltage display range is quoted as 5mV per division for HPS50 and 1mV per division for HPS140i - is this major division or minor division? Does the x10 function bring these down to 0.5mV and 0.1mV?
With HPS140 sensitivity, we mean the minimum voltage change that can be seen on the screen (i.e. when a pixel moves).
A division consists of 10 pixels and minimum setting is 1mV/div.
With the HPS50 it is different.
Minimum setting is 5mV/div, but sensitivity is still 0.1mV, here it refers to the resolution of the readouts.
Please keep in mind that with slow t/div settings, the number of samples is also very low, so if an event happens between to samples, it can remain undetected.
Thank you for the information VEL417 - am I right in saying then that the HPS140i is slightly more capable of displaying the voltage signal range I need than the HPS50?
I can see it would be right at the limit of its sensitivity though and might not give a reliable response. I did also want to pass the signal through to a PC somehow (probably USB) - and I don’t think the HPS140i allows this. Do you have any other oscilloscopes that would be better suited to the voltage range I need and also be PC/Mac enabled?
Yes, it is slightly more sensitive, but no USB.
Maybe a PC scope is better suited (although no mMac support)
Thanks again. From what you say, at 5mV/division, it sounds like the HPS50 is not capable of displaying a deflection of 0.1mV on screen (would the minimum on screen signal change displayed be 0.5mV - i.e. 10 pixels per division?).
I wondered though, if this is limited by the device screen resolution, is the signal passed through to a PC (via USB) more detailed - i.e. could a signal change of 0.1mV be displayed on the PC screen?
Finally, I have been looking at the WFS210 as an alternative/slight compromise. The sensitivity is given as 0.2mV, but minimum voltage display is again 5mV/div - what would be the minimum voltage change/deflection that can be displayed on the ios/android/pc software screen - i.e. how many active pixels per division? (I need to see the actual signal variation, not just the descriptive summary readout figures).
Thanks for your help - and sorry for the very detailed question.
The WFS210 samples the signal with an 8-bit AD-converter (256 bit).
The usable range: 3 to 252 (less than 3 and greater than 252 is off screen)
The highest sensitiviy is 5 mV/div.
Full screen: 10 division x 5 mV/div = 50mV
resolution: 50 mV / 250 bits = 0.2 mV
The app is so made that the height of the controls are the same on each device.The rest of the space is filled in by the raster.
So the height of the raster is variable. Let use 600 pixels in this example.
The max voltage that can be displayed without clipping is 50mV(5mV/DIV * 10DIVS).
So 50mV divided by 600 equals 83uV/Pixel. But its not the pixels that count but the points shown on the screen. As explained by my colleague above.
For indepth info i suggest to check out out githhub here