RKI Instruments Eagle Series - Manual (Page 62)

55 • Appendix B: Methane Elimination Eagle Instruction Manual
Appendix B: Methane Elimination
For applications where methane is an interfering gas, you can set the
Eagle to eliminate most response to methane. The methane
elimination switch is a standard feature on the circuit board inside the
top of the Eagle’s case. An external switch is available as an option. For
this type of detection, the combustible gas channel must be
programmed to display HEX or *** (see “Updating Channel Settings”
on page 26). Eagles with the external methane elimination switch are
factory-set with the correct display.
Setting up for Methane Elimination Mode
1. Take the Eagle to a fresh-air environment. Set the internal methane
elimination switch to the HEX ON position or the external switch
to Methane Response Off.
CAUTION: If the Eagle is equipped with an external methane elimination
switch, do not adjust the internal switch. The internal switch
should always be in the CH4 position.
2. Allow 2 minutes for the combustibles sensor to stabilize.
3. Perform the demand zero procedure as described in “Preparing
for Calibration” on page 42.
WARNING: DO NOT adjust the switch after re-zeroing the Eagle.
Response to CH
4
is greatly reduced when the internal
switch is set to “HEX ON” or the external switch is set
to “Methane Response Off”. If used for methane
detection, the internal switch must be set to “CH4” or
the external switch set to “Methane Response On”.
Operating with Methane Response Off
Monitor for combustible gas as you normally would. When the Eagle
is operating in Methane Elimination mode, response to methane is
reduced by 90% or more. Response to hexane is reduced slightly
(approximately 15%). To convert readings for most common
combustible gases, see Table 7 on page 56.
Returning to Methane Response Mode
1. Take the Eagle to a fresh-air environment. Set the internal methane
elimination switch to the CH4 position or the external switch to
Methane Response On.