Welch Allyn Propaq Encore, Service Manual

Page: 33 / 130

Service Manual Functional Verification 29
Mainstream CO
2
Verification Procedure
This procedure verifies the accuracy of the Encore’s mainstream CO
2
(MCO
2
)
measuring
system. If verification test results exceed specification limits, calibration ( “MSP Board
(MCO2) Calibration” on page 42) MAY or MAY NOT be required—there are multiple
possible sources of errors in testing as listed in the table “Possible Sources of CO2
Verification Test Errors” on page 30.
1. Connect a MCO
2
sensor with airway adapter to the Encore MCO
2
input connector.
2. Turn on the Encore. Press ALARM SUSPEND/RESUME to disable the alarms.
3. Press SETUP > MORE > MORE (>SERVICE > YES > MORE > MORE > SETTINGS,
for software versions 2.0 and greater) and then set the CO
2
measurement units to
millimeters of mercury (mmHg).
4. Allow the monitor and sensor to warm up for at least 15 minutes.
5. After 15 minutes, check that the CO
2
reading (of ambient room air) on the Encore
display is
1 mmHg, ±1 mmHg.
6. Install a rubber stopper in each end of the sensor airway adapter. (See “Required
Equipment” on page 12.)
7. Connect the CO
2
gas source through the hole in the stopper on one end of the airway
adapter. Leave the other end open.
8. Introduce a flow of test CO
2
at a rate of 60 to 200 ml/min into the sensor airway
adapter.
9. For test gas calculated partial pressure values of 30 mmHg or less, check the CO
2
reading on the Encore display to be within 3 mmHg.
10. For test gas calculated partial pressure values greater than 30 mmHg, check the CO
2
reading on the Encore display to be within ±10% of the partial pressure value.
11. Disconnect the test gas source and other test equipment.
1000 674.11 2700 546.23 4400 438.74 6100 349.05
Table 8. Local Uncorrected Barometric Pressure (LUP) as a Function of Altitude (Meters)
Altitude
(Meters)
Pressure
(mmHg)
Altitude
(Meters) Pressure
(mmHg)
Altitude
(Meters) Pressure
(mmHg)
Altitude
(Meters) Pressure
(mmHg)
Note Possible errors may be caused if the area has high background CO
2
levels or if
CO
2
has been forced outside of the airway adapter and into the sensor itself. To
reduce the background CO
2
level, the area should be well ventilated and,
preferably, the technician should be the only person present. If CO
2
has been
forced into the sensor, allow 24 to 48 hours for the CO
2
to dissipate.
Note
Before performing the following steps, convert the percentage of the gas source
to partial pressure (mmHg) according to the procedures in Mainstream
“CO2
Verification Preparation” on page 26.
Note If CO
2
test results are out of specification limits, check the table “Possible
Sources of CO2 Verification Test Errors” on page 30 for possible error sources.
Always verify the test setup to minimize errors.