Will do Darran , never thought of that !
The calibration value does not have a direct bearing on system pressure. The calibration value will depend on how hard the pump is running. The harder the pump is running the more current is drawn and the higher the cal value will be. Dead emd calibration is designed to stop the pump when a pole valve is closed before the pump pressure switch needs to open and in doing so protects the pressure switch.
Also the higher the flow rate is set on the controller the pump draws more current and Cal is based on that. My advice is that the chap set a flow rate they are happy with and then run auto cal.
Because of restrictions created in the hose driving a pump at 100% does not give much benefit. The reason for that is the hose has a maximum capacity it can carry, With a 100 meter of 8 mm ID hose and a 6mm ID pole hose the maximum is about 2.7 LPM at the brush head run flat out the pump is trying to force more water into the hose than it can carry and will draw 7 amps plus current. This puts a lot of strain on the pump motor and if the pressure switch opens under this load its more likely to arc and burn out. Setting the controller to around 65 flow rate will give the same 2.7LPM at the brush but with the pump drawing only 4 amps. There is also less load on the pump motor, and less heat generated.
At a flow of 65 Cal would come in around the 45 - 60 range at a guess and will give good flow. Hot water will make the hose wall softer and mean it expands a little more and quicker. With this set up Dead end cal nay be lower as the controller can be more sensitive .
Hope this help