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Performance Procedures
4-34 Testing the Monitor
CO
2
Gas
Measurement
Calibration
Check
After switching the monitor on, or after turning on the etCO
2
On/Off setting in the etCO
2
frame, wait at least 20 minutes before checking the calibration.
Step Action
1 Check that the 5% calibration gas and flow regulator are connected.
2 Calculate the expected measurement value in mmHg as follows:
0.05 x (ambient pressure) / 1.03 = value mmHg
i.e. 0.05 x 736 mmHg / 1.03 = 35.7 mmHg (with an ambient pressure of 736
mmHg)
Note: Dividing by 1.03 compensates for the dry calibration gas at room
temperature, relative to breath gases containing water vapor and at body
temperature.
3 Select CO
2
Calibration. Wait for the status message "CO
2
module reset in
progress" to disappear. Open the valve on the flow regulator to allow 5% CO
2
gas to flow into the monitor. Allow the displayed CO
2
value (third row of CO
2
Test menu) to stabilize.
4 Check that the CO
2
value on the monitor matches the calculated mmHg value
±2.6 mmHg. If the value is outside the tolerance, calibrate as described in Step 9
to 13.
5 Disconnect the 5% calibration gas and connect the 10% calibration gas.
6 Calculate the expected measurement value and tolerance in mmHg as follows:
0.1 x (ambient pressure) / 1.03 = value mmHg
±0.07 x (value mmHg) = tolerance
i.e. 0.1 x 737 mmHg / 1.03 = 71.6 mmHg (with an ambient pressure of 737
mmHg)
±0.07 x 71.6 mmHg = ±5.01 mmHg tolerance
7 Open the valve on the flow regulator to allow 10% CO
2
gas to flow into the
monitor. Allow the value to stabilize.
8 Check that the value on the monitor (X6) matches the calculated mmHg value
within the calculated tolerance. If so, the CO
2
module is correctly calibrated. If
the value is outside the tolerance, calibrate as follows.
9 If not already connected, connect the 5% calibration gas.
10 Select CO
2
Calibration to enter the Calibration sub-menu. Wait for the status
message "CO
2
module reset in progress" to disappear.
11 Select the value for the calibration gas (The default value is 5%).
12 Select Start Calibration and open the valve on the calibration gas to allow CO
2
gas to flow into the monitor. Allow the value to stabilize before the start of the
calibration. Leave the valve open until the monitor gives a prompt that the gas
can be removed.
13 The CO
2
module calibrates and prompts when calibration is successful.