(10-19-2014, 06:02 PM)TyroneShoes Wrote:(10-17-2014, 11:39 AM)retired_guy Wrote: I see on your sidebar your min pressure is set to 5. If that's so, then for you there is no difference between 1, 2 or 3 because the lowest the machine will go is 4...
That is partly true. The lowest a machine will go when set to a minimum pressure of 5 is 5, even though if the min is set to 4, the machine can go as low as 4. The whole idea of setting a min pressure is so that the machine can't go below it, even if the possible setting range is 4-20. EPR does not violate the min setting.
. . .
I don't have a manometer, so I haven't checked this, but my pressure range is 10 - 20, and I am running EPR 3. When I pull the SD card and look at the Pressure graph in SleepyHead, there are 2 lines: Pressure and EPAP. The EPAP line is a constant 3cm below the Pressure line. So every time I turn on the machine, Pressure starts at 10, and EPAP is at 7. Every time the pressure changes in response to events, flow limitation or whatever, the corresponding change occurs in the EPAP line - always 3cm less than the pressure.
You should be able to confirm this on your own machine: If you aren't using EPR already, turn on EPR to at least 1, then look at SH the next day. You should see an EPR line that is below your pressure line by the EPR setting. If you set EPR greater than 1, the difference will vary, since the machine cannot deliver less than 4cm. But whenever the pressure is 7 or greater, the EPR line should be a fixed amount below the pressure line.
PAPing in NE Ohio, with a pack of Cairn terriers