How to get large resistor 1 GOhm?

KeithWalker

Joined Jul 10, 2017
2,034
If you find one or make one out of several other lower value resistors, be aware thet you need to be extremely careful how you handle and mount it. What ever you use must have a very high dielectric constant. It must be protected from moisture and contaminents. A resistor with that high a value will just about change its value if you even look at it the wrong way!
 

MisterBill2

Joined Jan 23, 2018
9,792
I am building a capacitor tester.
That will be a very interesting device when it i completed. Years ago I studied the plans published for "the femtofarad Meter" as part of a work project. But we needed to measure dielectric absorbtion and its variation and changes with aging and temperature. So measuring capacitance was not enough, nor was measuring leakage current.
So what capacitor characteristic would the system be evaluating?
 

MisterBill2

Joined Jan 23, 2018
9,792

Ian0

Joined Aug 7, 2020
3,752
OK, those would be the non-electret capacitor microphones, the electret mics are so very small that a big resistor would not fit.
Yes - proper studio microphones, not telephone handset inserts.
https://www.andertons.co.uk/akg-c45...fJzpTnfYWKbhl82RjaD_f3tA93poNRaxoC33IQAvD_BwE
I have one that I use for noise measurements, but it's currently on loan to a friend who found it perfect for mic'ing the hi-hats on his drum kit.
The capsules are interchangeable, they can be unscrewed and replaced by ones with different directional characteristics. (Obviously, you don't do that in the rain, otherwise it would rather shunt the 10G load resistor!)
 
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