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Probe Problem

Probe Problem

Probe Problem

(OP)
Hello,
I'm having problems with my self-built measuring device.
The input stage looks like this:

  1V  ------3M6-----------n.inv. amplifier x1,6------- 1V
    |                |
    1,125M        5M4
    |                |
    GND             GND

When I connect a x1/x10 probe I get with 1V/10V applied to the tip 1V +-3mV at the output of the amp.
x1/x10 probe:    

     <-------9M---------->            
         |             |
         |__--____|


When I connect a x10/x100 probe I get with 10V at the tip and x10-range 0,987V?

x10/x100 probe (only x10 range shown):


     <----4,49M--------->
                      |
                      |
                      0,969M
                      |
                     GND

Why are the results so different?

RE: Probe Problem

(OP)
Hello again,
I've almost solved my problem smile
The 987mV is exactly the calculated result for the x10/x100 probe with 1MOhm input resistance.
To get 1000mV the 969k should be 976k or the 4,494M a little bit lower.
I don't know the real values, does anyone?
My biggest problem is:
Can I change the probe values by opening it without destruction?
And who delivers x10/x100 probes?
Thank you

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