RKI Instruments SM-2009U - Manual (Page 26)

22 • Connecting Calibration Gas
7. Use the BUMP ▼ and CAL. ▲ buttons to set the parameter to the
desired value, then press and release the EDIT ENTER button.
The “E” next to the battery icon will disappear.
8. Repeat step 5 - step 7 to set any other parameters.
9. When you are done setting the parameters, use the BUMP ▼
button to scroll past GAS-IN. The DECISION screen will appear
momentarily to indicate that the parameter changes have been
saved and then the GX-2009 will return to the TRANSMIT screen.
Connecting Calibration Gas
The CAL. GAS fitting on the back of the calibration station is designed to
be used with a calibration gas cylinder that is fitted with a demand flow
regulator. The AIR fitting may be used with a demand flow regulator and
a cylinder of zero emissions air, but this is not normally necessary since
the calibration station will generally be in a fresh air area.
The type of calibration gas cylinder used depends on the gas sensors
installed in the GX-2009 being used with the calibration station. A 4-gas
mix, LEL/Oxygen/CO/H2S, is used if the instrument being used with the
calibration station is a 4-gas unit. If the instrument does not have an H2S
channel, then a 3-gas mix, LEL/Oxygen/CO, is used. Although a 4-gas
cylinder will work for an instrument of any gas combination, if you have
multiple instruments with various gas combinations, you may want to
keep a 4-gas cylinder and a 3-gas cylinder to help preserve the charcoal
filter on the CO sensor in instruments without an H2S channel. Use
Table 4 below as a guide in determining which calibration gas cylinder is
appropriate for your system. See “Spare Parts List” on page 50 for a list
of available cylinder part numbers.
Table 4: Recommended Gas Cylinders
Typical Instrument Types
Recommended Calibration Gas
Cylinder
LEL/Oxy/H2S/CO 4-gas mix with LEL/Oxy/H2S/CO
LEL/Oxy/CO 3-gas mix with LEL/Oxy/CO
LEL/Oxy/H2S 4-gas mix with LEL/Oxy/H2S/CO
LEL/Oxy 3-gas mix with LEL/Oxy/CO