The Delay calibration, recommended to be carried out once per week or whenever the sampling line is replaced, is necessary to measure accurately
the time necessary for the gas sample to pass through the sampling line before being analyzed.
Note: Cellular phones should be turned off to eliminate potential electrical interferences.
Reference Gas calibration
The software allows to automatically calibrate zero, gain and alignments of the gases sensors. Even if the program doesn't force you to carry out the
calibration, the system should be calibrated before each test. To perform a sensor calibration, a cylinder with a known concentration of mixed gas is
necessary. It is suggested to use CO
2
5,00% , O
2
16% concentrations and N
2
for balance.
Note: After turning on the unit, wait 45 minutes warm up time before starting the calibration procedure.
Notice: Do not use mixtures with a O
2
concentration above 24% (out of the O
2
sensor range) or under 15%.
Notice: Before calibrating be sure the "Reference values" of room air and reference gas are properly entered.
1. Connect the pressure regulator for calibration to the calibration cylinder (if not connected yet)
Note: The cylinder must be open, but the pressure regulator must be closed
2. Connect the sampling line to the Sampling connector on the K5 unit and leave the other end free at the air
3. After flushing the analyzers, the system start calibrating the CO
2
zero and the O
2
span
Caution: During this first phase be sure to put the sampling line far from the exhaled gas otherwise calibration could
be affected.
4. When required, connect the free end of the sampling line to the pressure regulator and open the regulator
Note: If a message “Tank gas not detected!” is shown, please check if the cylinder is open and/or it is not empty.
5. At the end of the calibration, exit with the EXIT icon
Room Air calibration
Note: After turning on the unit, wait 45 minutes warm up time before starting the calibration procedure.
Important: During calibration always remove the sampling tube from the optoelectronic reader. Do not remove the
sampling tube from the Portable Unit otherwise calibration could be affected.
Caution: During Room Air calibration be sure to put the sampling line far from the expired gas otherwise calibration
could be affected.
Caution: Room Air calibration performed in small rooms (high concentration of CO
2
) affects the calibration results
and the accuracy of the following test.
1. Connect the sampling line to the Sampling connector on the K5 unit and leave the other end free at the air
2. After flushing the analyzers, the system start calibrating the CO
2
zero and the O
2
span
3. At the end of the calibration, exit with the EXIT icon
Delay calibration
The delay calibration procedure is a calibration included in the software due the time alignment between flow and gas concentration
measurements is one of the potential problems to consider to assure accurate readings during test. The gas delay calibration is the measurement of
time required by the gas to reach the gas analyzer.
For "breath by breath" analysis it is essential that the instantaneous flow rate must be multiplied by the proper time-matched expired gas
concentration. Although flow can be instantaneously measured, gas concentration measurements can be calculated with a delay related both to
the time necessary for the gas to be transported to the sensor and to intrinsic characteristics of the analyzer principle.
46 - K5 Operation - Calibration
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