7
GG-R
Operation
Start-up
Before applying power, make a final check of all wiring.
After power-up, allow at least 1 hour for the system to
stabilize before testing the sensors. Because sensors
are normally located at a distance from the main unit,
the test time required and accuracy of the response
checks will be improved if two people perform the
start-up procedures and use radio contact.
Start-Up Test:
1) One person exposes each sensor to a gas sample or
calibration gas.
2) The second person stays at the control unit to
determine that each sensor, when exposed to the
target gas, is connected to the proper input and
responds, causing appropriate alarm functions.
Calibration
The GG-R Sensor comes factory calibrated and should
require only minimal adjustments after installation.
There are two pots on the preamp that are used for
calibration.
Note: Never measure sensor output in mA. Always
use mVDC (or VDC) voltmeter settings.
Note: The adjustment response is dampened. Make
slight adjustments (no more than ½ turn of the
potentiometer) and wait for output response.
Zero Calibration:
After the unit is installed and has
been powered up for a minimum of 1 hour, the unit
can be zero calibrated by the following:
• Activate calibration mode by pressing the CAL
MODE button (green LED will flash).
• Proceed to next step if certain the sensor is in clean
air (no target gas present), otherwise apply Zero Air
gas at 0.8 L/min.
• Adjust the zero pot until the sensor outputs 40
mVDC from test points [-] to [+] (see Figure 2).
Span Calibration:
Perform zero calibration prior to
spanning.
• Activate calibration mode.
• Connect tubing to the calibration port of the
infrared tube. (see Figure 2)
• Apply span gas at 0.5 to 0.8 L/min.
• Sensor should react to gas within 20 seconds.
• Once the output signal has peaked (or 3 minutes
maximum) adjust the span pot until the correct
output is achieved.
• Exit calibration mode by pressing the CAL MODE
button (green LED will stop flashing).
• Replace cap over calibration port
Note: Calibration mode will automatically time-out
after 6 minutes.
If the correct output cannot be achieved, contact
Calibration Technologies for technical help.