GasWatch 3 for CO and O
2
Chapter 5: User Mode and Calibration • 49
Performing a Span Adjustment in E-CAL
The
E-CAL
item only appears if
E-CAL
in User Mode is set to
ON
(factory setting is
OFF
).
If
E-CAL
is set to
OFF
, see pg.44 for calibration instructions.
Preparing for Span Adjustment
To adjust the span on the GasWatch 3, you need:
•
Calibration gas cylinder (RKI Instruments recommends using 50 ppm CO)
•
0.25 LPM fixed flow regulator
•
Non-absorbent tubing
•
Calibration cup
1. Confirm that the GasWatch 3’s calibration gas values match the concentrations listed on
the calibration gas cylinder as described on pg.54.
2. Confirm that the regulator knob is turned all the way clockwise. Screw the 0.25 LPM
fixed flow regulator onto the calibration cylinder.
3. Install the calibration cup onto the GasWatch 3. The calibration cup has an indicated flow
direction. Be sure the calibration cup is installed in the correct direction and that it is
pushed on all the way.
4. Use the tubing to connect the regulator to the inlet of the calibration cup.
Performing a Calibration
1. While in User Mode, press AIR to scroll to
GAS CAL
.
2. Press and release POWER/MODE. The
AIR
item appears.
3. Use AIR to scroll to the
E-CAL
item.
GAS CAL
E-CAL
