Thanks Yeez_B

From the 5V power supply, I connect positive to the red wire and negative to the black wire.  Then I measure the voltage between the yellow wire and the black wire.

I have attached the sensor to the output pipe of my demand pump set at 350kPa and it doesn't go up.  I don't think it will help to use higher pressure, as that is the range that I am needing to measure at.