.234 sounds too low. I don't know if the 3000 series had different parameters than the 3300 series. I think you'd see somewhere between 2 V and 22 Volts on the 3300 hundred whether the probe was touching or very far away.
You could use a voltage divider to drop the voltage. A pair of matched resistors of high impedance. You input the signal across both resistors in series, and measure the voltage at the half way point relative to the one common end.
Have you tried contacting Bently Nevada? Do you have instruction manuals for your system?
