TR9277-EO Manual
Page 8 of 12
test (
Green
LED) and range confirmation test (amber). When the
Amber
LED is blinking, go to
step 3. (If the 3 LEDs fail to blink during this test, place under a lamp with at least 100 fc (1000
lux) for 1 hour before retrying.)
3.
Press and hold the test button again for 6 seconds to select Range Confirmation Test.
All three LED’s can blink in this test mode when the sensor transmits or receives a Range
Confirmation Telegram. The sensor will display the signal strength status for 5 seconds, see table
below.
Table 2: Range Confirmation Test Table
LED
Signal Strength
Green
> -70 dbm
Red
< -80 dbm
The test will repeat every 10 seconds and run for a duration of 3 minutes. You may quit the test at
any time by pressing the occupancy/test button for 6 seconds.
7.3
CO
2
Sensor Calibration & Set Up
There are two types of adjustments that can be made to the
CO
2
sensor:
•
Turn off or on the Automatic Background Calibration (ABC) feature.
•
Commissioning/Calibrating the sensor to outside air or a known value.
7.3.1 Automatic Background Calibration Activation
The
Automatic Background Calibration (ABC)
is a feature that looks at the lowest level of
CO
2
that
occurs over a 3 week period and assumes it is an outside background level of 420 ppm. This feature
works best where the space being monitored is periodically unoccupied for 8 hours or more in evenings
or weekends at least once in a typical 3 week period. When in this mode there should be no need to
calibrate the sensor over its operating life. The ABC feature is on by default.
If the space being monitored is occupied 24/7 or is an industrial or greenhouse operation where
elevated
CO
2
levels may be sustained over long periods of time, then the ABC feature should be
turned off.
7.3.2 Calibration/Commissioning Modes (Insertion of a battery is highly recommended)
It is recommended that the installer perform an ambient air calibration of the TR9277-EO as part of the
installation process. This process takes 10–15 minutes and can be performed on site or prior to visiting
the site. Multiple sensors can be calibrated at the same time.
1.
Place the sensor(s) in outside air above 32ºF (0ºC), and out of direct sunlight for 10 to 15 minutes.
Avoid breathing in the vicinity of the sensor during this process.
2.
Follow the process outlined below for performing an ambient air calibration. Again avoid
breathing directly on the sensor when activating the function button.
3.
Once calibration is initiated, the Amber LED will blink rapidly. Put the sensor down and stay away
from the area for 2 minutes while the calibration process occurs.
4.
Once the calibration is complete the Green LED will blink 10 times and return to normal operating
mode.
Amber
< -70 dbm, > -80 dbm
