Synetica enLink Air - Quick Start Guide Rev 2.0 Page | 8
Please see the table below for information on each menu item.
Shows the last CO2value read and the minimum CO2value read since the last auto
calibration.
Shows when the next autocalibration routine will occur
Shows the value of the last auto calibration result. Used internally by the sensor.
This shows the total number of successful auto calibrations since the device was powered
up.
Shows the number of times that auto calibration did not run due to the Out Of Bounds
setting.
E - Enable/Disable
Auto-Cal
Enables or disables the auto calibration routine.
This is the known CO2corresponding to the minimum value the sensor has read since
power-up or last calibration. It is normally 'fresh air' or the lowest level when the building is
unoccupied
overnight or at weekends. Typically this is 400 ~ 450 ppm.
K - Set to Known CO2
Level
This will re-calibrate the zero point of the sensor to a known gas concentration. The sensor
should be placed in this gas concentration and allowed to stabilise.
This command runs in the background and will take 8 to 10 seconds to complete.
As an example, fresh air is typically around 400 ~ 450 ppm.
The Out-of-bounds value is used to ignore the calibration if the minimum value the sensor
has read is not within a sensible range of the target concentration level.
So, if the target concentration level is 400, the Out-of-bounds value is ±50 and the
minimum reading is 451 (or more), the calibration routine is ignored.
It is possible for the first auto-calibration to take place more quickly than the regular auto-
calibration events. This can be useful to stabilise the readings quickly after installation.
This is the standard calibration interval, it is set to 8 days by default to accommodate a
week long period where the minimum sensed CO2level should have fallen to background
levels.
The CO2sensor needs to be exposed to fresh, clean air periodically for the auto calibration to be successful. Most occupied
areas are unoccupied for some time during a week-long period, typically at night, or at the weekend and therefore the auto
calibration runs every 8 days by default. Background CO2levels are typically around 400-450 ppm, if the background CO2
level is known to be a different value then this can be set in the “Set Target CO2Level” parameter
If a unit is placed in an area where the CO2level may not fall below a certain level, e.g. 450ppm, during the calibration
interval then the “Out-of-bounds check” parameter can be set so that the auto calibration routine does not run. As an
example, if an area is continuously occupied for a long period and the minimum CO2reading does not fall below, say
450ppm, then it is undesirable to run the autocalibration routine based on a target of 400ppm. In this case, if the “Set
Target CO2 Level” is set to 400ppm and the “Out-of-bounds check” value is set to +/-50 ppm then the autocalibration
routine will not run unless the minimum read value falls below 451ppm in the interval.
6. Live Menu
enLink Air incorporates a live data screen which shows all readings and device status for easy data validation. To enter the
Live status screen, from the Main Menu enter c for Configure Device followed by dfor Live readings display. A screen
similar to the one below will show. The sensors will vary according to the enLink Air model and the installed sensors.
