Hi, my name is Martin I have run my small shop with my brother in West Yorkshire England from 1984. We have been into diagnostics for about 10 years and Pico users for the last 6 years. You can see me on video here on page 9.
http://content.yudu.com/A1jayq/Ai4/resources/3.htm
Hi Tom thanks for the invitation to the forum.
For your questions;
What kind of pressure transducer did you use?
This is bolted off a car, a Bosch pressure sensor that is located in the common rail.
Where was the Pico ground lead attached?
The sensor has 3 pins, 5 volts supply and ground (and Pico ground) from a lab voltage unit and the signal pin that the Pico probe is connected to.

Hope that’s a little clearer Tom regards Martin.