Products > Test Equipment
Is my hantek DSO2C10 bad/inaccurate?
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powerstroke7.3:
New here. Not really knowledgeable on scopes. This is like my 3rd scope.
New from amazon. Did the dso2d10 to dso2c15 conversion.
The scope reads random mv reading without anything hooked up.  I was testing a inline power meter and went down the rabbit hole and saw my scope  reads high. My ham radio samlex sec1235m ps reads 14v on one ch and 14.1 on the other. My fluke 16 reads 13.85v ive tested some 1.5v aa batteries and it reads 1.60v on a 1.44v  battery
This cant be normal.
Heres a video of what I am seeing
https://youtu.be/RxbomZHTxQg
ataradov:
Scopes are not multimeters, their accuracy, especially on high V/div setting is not good. You can only do so much with 8-bit ADC.

Your full screen vertical display is 5 V/div * 10 div = 50 V. 8-bit ADC can show 256 values. Assuming the screen shows full scale ADC range, one LSB is 50 / 256 ~= 200 mV. You can see your reading jump by that much.  This is ADC changing its value by 1 count. This is the best it can do.

Scopes are not good at dealing with high voltages. That's (among other things) why there are 10x probes - to bring the input voltage into an acceptable range.
powerstroke7.3:

--- Quote from: ataradov on August 31, 2022, 04:10:15 am ---Scopes are not multimeters, their accuracy, especially on high V/div setting is not good. You can only do so much with 8-bit ADC.

Your full screen vertical display is 5 V/div * 10 div = 50 V. 8-bit ADC can show 256 values. Assuming the screen shows full scale ADC range, one LSB is 50 / 256 ~= 200 mV. You can see your reading jump by that much.  This is ADC changing its value by 1 count. This is the best it can do.

Scopes are not good at dealing with high voltages. That's (among other things) why there are 10x probes - to bring the input voltage into an acceptable range.

--- End quote ---
seems like it should be accurate at 12v stuff. Im not trying to read millivolts. Even probe compinsation reads funny
ataradov:
It is irrelevant what things seem like. I explained the math. It does not matter what the input voltage is, what matters is V/div setting. With your setting the resolution is 200 mV, so the minimal difference it can notice is 200 mV.

Use 10x probe and it would be more accurate.
pcprogrammer:
If you bought a scope with the idea to accurately measure some DC voltage, than you have a wrong perception of what scopes are for.

A scope is for visualizing signals. Use your DMM to get an average reading of the DC level and your scope to get some insight in the noise on top of this DC level. So connect a 10x probe, select AC input on the channel and dial the sensitivity to mV/div range. This way you can see how much noise there is on your DC supply output.

A fat chance it is way more then 200mV peak peak.
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