User Manual

5.4 Analysis
Recommendations to ensure an accurate mix:
Adapters, tubing, flow manifold and all three (3) sensors must be free of
liquid before attempting to calibrate or use the AII-4001
Avoid high flow rates which may cause inaccurat e readings
Expose the sensors to clean air f or several minutes to ven t p r evious mix
Calibrate the AII-4001 as described in Section 5.3
Follow estab lished g uidelines for allow ing the mix to cool after ea ch trans-
fer of helium and oxygen.
1) Install the flow manifold (Note : the flow ma nifold is b i-directiona l) as illus-
trated at left on page 7.
2) Connect tubing to the dome adapter and the flow manifold. (Note: Dome
adapter may be replaced by other optional equipment, in the case regu-
late pressure to <5 psi and control flow rate between 1-2 lpm.)
3) Open the tank valve very slowly until you hear t he gas his sing out.
4) Press the dome adapter tigh tly against the tank ou tlet as illustrated below.
5) Allow sufficient time, approximately 30 seconds, for the readings helium,
oxygen and balance gas to stabilize.
6) Record your readings and close the tank valve.
7) For mul tiple cylind er chec ks,
a. Remove the bi-directional flow manifold.
b. Expose the sensors to clean air f or several minutes to allow the
previous mix to vent into the atmosphere.
c. Repeat steps 1 throug h 7.
10
5.3 O
2 Calibration and He Zero
The AII-4001 employs proprietary maintenance free long life Helium and Oxy-
gen sensors that measure in the 0-100% range. The Oxygen sensor is auto-
matically compe n sated d uring calib ratio n for temperature , rela tive humidity an d
pressure, thereby eliminating the need for conversion charts. The Helium sen-
sor is characterized using a six point linearization curve. Further, the Helium
output is compensated for differences in thermal conductivity of Oxygen and
Nitrogen. Whether the source is ambient air or compressed gas, the AII-4001
enables the user to automatically calibrate the Oxygen sensor and zero the
Helium sensor with a single touch. The result is the most accurate analysis of
your trimix.
O2 Calibration/He Zero wi th Am b ient Air:
1) Rem ove the flow manifold, if necessary , as illustrated b e low .
2) Exp ose sensors to clean ambient air for several minutes.
3) Press GREEN CAL O
2
ZERO He key.
O2 Calibration/He Zero with Span Gas:
1) Adapters, tubing, flow manifold and all three (3) sensors must be free of
liquid before attempting to calibrate or use the AII-4001.
2) Avoid high flow ra tes which may cause inaccurat e readings
3) Install the bi-directional flow m a nifold as illustrated below.
4) Connect tubing to the dome adapter and the flow manifold. (Note: Dome
adapter may be replaced by other optional equipment, in that case regu-
late pressure to <5 psi and control flow rate between 1-2 lpm.)
5) Open the tank very slowly until yo u hear the gas hissing out.
6) Press the dome adapter tightly against the tank outlet as illustrated right
on page 8.
7) Allow the air to flow for several minutes.
8) Press the GREEN CAL O
2
ZERO He key.
9