Calibration
The Calibration menu is accessible by pressing the related icon from the Home menu.
Regular calibration is necessary to assure your system is acquiring reliable measurements.
Calibration frequency
The table below shows a summary with the calibration intervals recommended by COSMED.
Calibration Recommended interval
Turbine
Each week, if the flowmeter is changed, if the ambient conditions (temperature, humidity and pressure)
change significantly and in all the cases you suspect that the measurements are not reliable anymore
Room air Each day and before each test
Reference gas Each day and before each test
Delay Once a week or when the sampling line is changed
Flowmeter calibration
This function allows the user to calibrate the flowmeter, correcting the errors caused environmental changes that may affect the turbine, repeated
use, obsolescence, etc.
Flow/volume calibration is performed using a 3-liter calibration syringe. If the syringe is not included in the packaging it can be ordered directly
from COSMED, REF C00600-01-11.
Each flowmeter requires a separate calibration.
Note
: If an anti-bacterial filter is used during testing, you should also use one when performing the turbine
calibration.
Flows and volumes are measured by the bidirectional digital turbine, which offers a very low resistance to flow. Air passing through the helical
conveyors cause the spiral rotation of the turbine rotor.
The rotating blade interrupts the infrared light beamed by the two diodes of the optoelectronic reader.
The turbine flowmeter does not require daily calibration since it is not affected by pressure, humidity and/or temperature. However, regular
calibration should still be performed as well as the recommended maintenance procedures (see System maintenance).
Perform a turbine calibration
1. Connect the turbine to the optoelectronic reader and this one to the K5 unit
2. Connect the calibration syringe to the turbine
3. Begin with the syringe piston pushed all the way in. When the unit is ready, move the piston in and out for 6 inspiratory and expiratory strokes.
The values will be automatically displayed.
4. At the end of the calibration the inspiratory and expiratory gain are shown
5. Exit with the EXIT icon.
Preface to the analyzers calibration
The system allows three calibrations:
1. Reference gas calibration
2. Air calibration
3. Delay calibration
The Room air calibration, forced by the system before every test, consists of a sampling room air. It updates the baseline of the CO
2
analyzer and the
gain of the O
2
analyzer, in order to match the readings with the predicted atmospheric values (20.93% for O
2
and 0.03% for CO
2
).
The Reference gas calibration consists of sampling a gas with a known composition (i.e. 16.00% for O
2
and 5.00% for CO
2
) from a calibration
cylinder, and updating the baseline and the gain (span) of the analyzers in order to match the readings with the predicted values (i.e. 16.00% for O
2
and 5.00% for CO
2
).
K5 Operation - Calibration- 45
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