Connect one end like you see in Picture #2 to the test port for the lower chamber. Connect the other end to the upper chamber via the cold start outlet on the fuel distributor. If your EHA is functioning properly you should get a differential of .4 bar while pressure is on. The put pressure on the system remove your fuel pump relay and bypass the connectors to get the pump to run.

Another way is to read the upper chamber alone, then connect to the lower chamber and subtract the results. This is acceptable if you have a simple gauge with a single test line.