Tektronix Technical Forums are maintained by community involvement. Feel free to post questions or respond to questions by other members. Should you require a time-sensitive answer, please contact your local Tektronix support center here.
I've encountered this issue on two different kind of text fixtures where I only have 2 electrodes - either planar or cylindrical and I want to measure an insulator. How am I to connect the Ammeter and to measure the current in this situation? When I had a guard electrode things were simpler, because I could link the V-SOURCE LO and just use the measuring electrode to get the AMMETER HI signal. But now with just two electrodes something's eluding me and I hope you can be of assistance.
The obvious first step is to connect the V-SOURCE HI to one side of the sample and the AMMETER HI to the other side of the sample.
Then I am puzzled.
a) Should I connect the V-SOURCE LO to the AMMETER LO (and AMMETER GND) either via physical connection or by simply using the internal-connect on the Keithley device and now with them together connected to link them to the actual GROUND ?
b) If I use the INTERNAL-CONNECT option I no longer have to any use wires to connect any of the two LOs and just keep the Keithley device grounded?
c) Or I only need to use 1 wire (for AMMETER LO, considering that the V-Source LO is internally connected to the AMMETER LO), and I put that to the chassis/ground, while also having the Keithley grounded?
d) Or should I not use the V-SOURCE AT ALL and just feed the AMMETER HI to one side of the sample and the AMMETER LO to the other side?
Please check the attached diagram.
Depending on how I connect the LO wires I get different results, and they differ by as much as two orders of magnitude between them.
If I connect HI V-SOURCE and HI-AMMETER on each electrode and the LO V-Source and LO-AMMETER to the ground (with the GND-AMMETER to the ground as well) and I go through the Kickstart software and run a simulation, I get nA currents with + (plus) and - (minus) signs. So I am confused, because I feel that this is the right configuration .... but I get crazy current values.
Please help me.
- Keithley Applications
- Posts: 402
- Joined: June 10th, 2013, 6:00 am
- Country: United States
Who is online
Users browsing this forum: No registered users and 1 guest