Welch Allyn PROPAQ CS - Manual (Page 34)

30 Functional verification Welch Allyn Propaq CS Vital Signs Monitor
18. Close the paper door and set the monitor upright.
19. Simultaneously press the PRINT TRENDS and START/STOP buttons.
20. Check that a test printout similar to one shown in the figure below is printed.
CO
2
verification preparation
The mainstream and sidestream CO
2
functional verification procedures require calculating
the local barometric pressure and partial pressure of the test gas (in mmHg) to compare
to monitor displayed values.
Local barometric pressure
The first step is to determine the local barometric pressure:
1. Determine local altitude above sea level.
For worldwide locations, obtain altitude from local geological maps (U.S.G.S. maps in
the United States) or other local references on the maps. Refer to the table titled:
Uncorrected Barometric Pressure as Function of Altitude; use this table to determine
the local uncorrected pressure (LUP).
2. Determine ATIS reported pressure (inches or millimeters of Hg).
For U.S. locations, consult local telephone directories to obtain the Automated
Terminal Information Service (ATIS) number, typically listed under United States
Government Offices, Department of Transportation, Federal Aviation Administration,
and Air Traffic Control Towers.
Among various statistics reported is the “altimeter,” which is given in four integers.
The four digits represent the barometric pressure as referred to sea level, in units of
inches of mercury, with an assumed decimal point occurring between the second and
third numbers.
For worldwide locations, equivalent altimeter statistics, in millimeters of mercury,
may be obtained from local agencies.
3. Determine local barometric pressure using LUP and ATIS. Apply the ATIS and LUP
values to the following formula to calculate the local barometric pressure (mmHg):
Local Barometric Pressure =
0.033421 x LUP x ATIS (ATIS in inches of Hg)
0.00131579 x LUP x ATIS (ATIS in mm of Hg)
Example 1
a. The altitude is 5000 feet. The local uncorrected pressure (LUP) is determined
from the following table to be 632.35.
Note The difference in altitude between the calibration site and the ATIS site should not
be greater than 30 m or 100 ft.