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"Calibrated" E4991a gives same result for all mate

Question asked by inverse_era on Sep 12, 2008
I will list my equipment set up at the end.

I am able to generate the e' and e'' graphs for DI water to match the expected outputs (see the attached file:"expected outputs.ppt").  The problem is that any substance that I measure generates a curve that sits on top of the DI water curve with a few tiny peaks.  What could be causing this?

Measured that generated DI water curves:
70%Isopropylnol+30%water
Pure Ethanol
2 PTFE blocks with dielectric grease between them

Here is my calibration process:
1)Ensure Software on computer communicates w/ Agilent E4991a
2)System preset E4991a & hold (stop) any triggering
3)Change mode to Permittivity
4)Calibrate E4991a w/ original test head (Open, Short,Load)
5)Connect option 010 test head to E4991a
6)Give trigger control to the PC (single, source=GPIB Bus, trigger event=sweep)
7)Set-up 85070D probe calibration (air/short/water)
8)set frequency 15 MHz-2GHz, linear sweep
9)verify E4991a reconfigures to settings in above step
10)Calibrate 85070D probe (using clean DI water, with no air bubbles

My equipment :
Agilent E4991A
85070 Dielectric Probe software
8507E usb Key
E4991U-010 Probe station connection kit
85070D Probe & calibration kit  

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