On the trip to S15 yesterday (Oct 20), took a photo of the EC100 internals, to help address the issue why Pirga seems to be low by about 1 mb.  It's probably not of much use, but here it is.

 

Around 11:25 EDT I  rserial'd to the EC150 on S15 (port 5).  The  pressure setting can be changed with the "O" command.  It is a hassle because we don't know how to  disable the unprompted output, and so the menu prompts are interspersed in the binary output.

Here's what t looks like  the response to the O command:
0) Pressure Source:\r\n1) Pressure Calibration:\r\n2) Differential Pressure Select:\r\n3) Temperature Source:\r\nEnter Selection:
Entered "0" (zero) and got:
0) Internal\r\n1) External\r\n2) CS106 (External)U\r\n3) Fixed PressureU\0xaa
Entered 1 for the external barometer.  However, then Pirga went to 22 and the h2o and co2 values became NaN.  Switching it back to the internal barometer resulted in Pirga=1008, and the h2o and co2 values returned.  
From Steve Oncley:
So...it is a mystery why the "external" barometer isn't working and why this box apparently was set to use the "internal" barometer.  I thought it had been working using the external.  This sensor was used in CABL.

12:30 EDT, queried pressure calibration:
O (pressure menu)
1 (pressure calibration)
1 (external)

Response (with the binary output removed):

Current Calibration values for external pressure: Gain = 1.000000, Offset = 0.000000
Enter new Gain and Offset (comma separated):

 

I didn't change these values.