Welch Allyn PROPAQ CS - Manual (Page 35)

Service Manual Functional verification 31
b. The reported ATIS is 30.09 inches Hg. (Altimeter: three zero zero niner.)
c. Multiply the LUP (632.35) by the ATIS (30.09) times 0.033421.
This gives the local barometric pressure of 635.92 mmHg.
Example 2
a. The altitude is 1000 meters. The local uncorrected pressure (LUP) is determined
from the following table to be 674.11.
b. The reported ATIS is 764.29 mmHg.
c. Multiply the LUP (674.11) by the ATIS (764.29) times 0.00131579.
This gives the local barometric pressure of 677.92 mmHg.
Partial pressure of test gas source
To determine the partial pressure of test gas source multiply the local barometric pressure
(as determined in step 3 above) by the certified percentage (±0.01% accuracy) of the test
gas.
Example
The local barometric pressure (as calculated in Example 1 above) is 635.92 mmHg.
The certified CO
2
gas percentage is 5.00%.
Determine the CO
2
partial pressure by multiplying (635.92) x (0.0500).
This gives the partial pressure of the CO
2
as 31.8 mmHg.
Table 8. Local uncorrected barometric pressure (LUP) as a function of altitude (feet)
Altitude
(feet)
Pressure
(mmHg)
Altitude
(feet)
Pressure
(mmHg)
Altitude
(feet)
Pressure
(mmHg)
Altitude
(feet)
Pressure
(mmHg)
-2000 816.56 1000 732.93 4000 656.38 10000 522.65
-1900 813.66 1100 730.27 4200 651.52 10333 515.93
-1800 810.76 1200 727.62 4400 646.68 10667 509.26
-1700 807.87 1300 724.97 4600 641.88 11000 502.69
-1600 804.99 1400 722.33 4800 637.10 11333 496.18
-1500 802.11 1500 719.70 5000 632.35 11667 489.72
-1400 799.25 1600 717.07 5200 627.64 12000 483.34
-1300 796.39 1700 714.46 5400 622.95 12333 477.04
-1200 793.54 1800 711.85 5600 618.28 12667 470.78
-1100 790.70 1900 709.25 5800 613.65 13000 464.60
-1000 787.87 2000 706.65 6000 609.04 13333 458.50
-900 785.05 2100 704.07 6200 604.47 13667 452.44
-800 782.23 2200 701.49 6400 599.92 14000 446.46
-700 779.42 2300 698.92 6600 595.40 14333 440.55
-600 776.62 2400 696.36 6800 590.90 14667 434.68