2004 CME INTERCOMPARISON SYSTEM PROCEDURES

1) Initialization
a) Connect cylinders A, B and C to each of the three regulators according to labels on the regulators and cylinders.
b) Make sure the regulators are all the way unscrewed, then open the cylinder valves till the pressure reaches maximum, and shut off again
c) Screw in regulator adjustment until pressure is vented (you will need to move the 4-way valve to the correct position as you do this for each tank)
d) Repeat three more times for each tank. 
e) Open all 3 cylinder valves and record the high gauge pressures again.

2) USGS (Dean's) System
a) Cycle 4-way valve, adjusting regulator output to barely permit flow while flushing each line for 15-30 seconds.
b) Connect common tube male quick connect to existing female quick connect on brass 3-way valve (in middle of main shelf, upstream of LiCor and downstream of selector valves)
c) Press *5 on CR10 controller and record datalogger time
d) Press *6,A,A and note selected line in position 3
e) Press *6,A,A,A,A,A,A,A and record LiCor pressure in position 7 (~560 mbar)
f) Avoiding calibration periods, which are for 60 seconds every even 2 hours in datalogger time, switch 3-way valve and record datalogger time
g) Press *6,A,A,A,A,A,A,A to get to LiCor pressure, and adjust regulator so that LiCor pressure matches sample pressure recorded earlier (+/- 10 mbar) – on 8/9, used A=7 psi, B=0 psi, and C=0 psi.
h) Once pressure has stabilized, record time and pressure and allow LiCor to measure for at least four full 30 second cycles (CO2 reading on Licor face can be monitored for stability).
i) Cycle 4-way valve and again adjust current regulator to match sample pressure
j) Remain on each position for at least four full cycles
k) Switch 3-way valve back and record datalogger time and line
l) Leave 4-way valve in open (off) position and disconnect quick connect.

3) CU (Sean's) System
a) Cycle 4-way valve, adjusting regulator output pressures to A=20 psi, B=20 psi and C=20 psi while flushing each line for 5-10 seconds.
b) Connect male quick connect to female quick connect on brass 3-way valve (on output line of green span tank at base of tower).
c) Open LiCor box on second level and note line position (some of the indicator lights are very dim).
d) Avoiding calibration periods, which are for several minutes every even 4 hours in local standard time (1, 5, and 9 MDT), toggle auto-man switch to man, toggle C2 switch, and record time and line
e) Return to base of tower and record line pressure on gauge attached to 3-way valve (~20 psi)
f) Switch 3-way valve to sample cal gases
g) Cycle 4-way valve, remaining on each position for 3 minutes and adjusting regulators at start of each period to match the line pressure +/- 1 psi – on 8/9, used A=25 psi, B=22 psi, and C=22 psi.
h) Switch 3-way valve back, toggle C2 switch and auto-man switch to auto, record time and line, and close LiCor box
i) leave 4-way valve in open (off) position and disconnect quick connect.


 
4) HYDRA (Tony's) System
a) Cycle 4-way valve, adjusting regulator output to barely permit flow while flushing each line for 15-30 seconds.
b) Connect common tube male quick connect to existing female quick connect on stainless 3-way valve (on lower left of instrument box)
c) Open instrument box and note line pressure (~9 psi) and flow (~30).
d) Note line indicated by lights on back of wooden box (S1-S9 and D).
e) Avoiding calibration periods, which are after each run through 18 sample lines (sequence is S1-S9 with D off and S1-S9 with D on for 93 seconds each, then a calibration with 1 or 4 gases run for 2 minutes each), switch 3-way valve and record time and line.
f) Adjust regulator to match line pressure to +/- 0.5 psi – on 8/9, used A=6 psi, B=0 psi, and C=0 psi.
g) Once pressure has stabilized, record time and pressure and allow LiCor to measure for at least 2 minutes (CO2 reading on Licor face can be monitored for stability). 
h) Cycle 4-way valve, remaining on each position for at least 2 minutes and adjusting regulators at start of each period to match the line pressure.
i) Switch 3-way valve back and record time and line.
j) Leave 4-way valve in open (off) position and disconnect quick connect from 3-way valve

5) AIRCOA (Britt and Andy’s) Systems
a) Cycle 4-way valve, adjusting regulator output to 10 psi while flushing each line for 15-30 seconds.
b) Connect common tube male quick connect to existing female quick connect on guest cal position (on bottom of box)
c) Open instrument box, connect palmtop to COM2 and run /rr.job command.
d) Note line selected and flow and pressure for both fast and slow flow modes.
e) Avoiding 4-point calibration periods, which are for 15 minutes preceding each even 4 hours UTC, turn all valves off except guest cal (11) and fast flow (12) and record time.
f) Adjust regulator to match fast-flow pressure to +/- 0.5 kPa – on 8/9, used A=10 psi, B=8 psi, and C=8 psi.
g) Once pressure has stabilized, record time and pressure and allow system to fast-flow for at least 30 seconds.
h) Close fast flow valve (12) and allow system to slow-flow for at least 2 minutes (CO2 reading can be monitored for stability).
i) Cycle 4-way valve and toggle fast-flow valve (12), remaining on each position for at least 30 seconds of fast-flow and 2 minutes of slow flow and adjusting regulators at start of each fast-flow period to match the line pressure.
j) Return to computer control of system (‘r’) and disconnect palmtop.
k) Leave 4-way valve in open (off) position and disconnect quick connect.
 
6) Shutdown
a) Close all 3 cylinder valves
b) Put packframe under a tarp at CU, Willow, or Aspen towers or cover regulators with a plastic bag.
c) Enter field worksheet into online log

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