36 • Chapter 3: Operation
GX-6000 Operator’s Manual
Using Optional Sample Hoses
The standard sample hose for the GX-6000 is 3 feet long. Optional samples hoses and
probes with longer hoses are available from 5 - 50 feet in 5 foot increments (see “Chapter
7: General Parts List” on page 128). If you are considering using a hose and probe with a
longer hose, keep in mind that a longer hose will increase the GX-6000’s response time
and the flowrate may decrease close to the low flow alarm point.
CAUTION:
Sample hose lengths of more than 50 feet are not recommended for the GX-
6000 because of flow rate reduction and increased response time. Consult
RKI Instruments, Inc. for hose lengths longer than 50 feet.
The chart below illustrates how response time is affected by the sample hose length.
Combustible Gas Detection
There are three issues to keep in mind when monitoring for combustible gas.
•
The catalytic combustible sensor will respond to any combustible gas. The standard
calibration gas for the GX-6000 catalytic combustible channel is methane (CH
4
). If the
instrument is calibrated to a different combustible gas, such as hexane or propane, the
gas name for the catalytic combustible channel will reflect the target gas.
The table below lists the conversion factors for several hydrocarbon gases
if the GX-
6000 is calibrated to methane
. To use this table, multiply the display reading on the
combustible gas channel by the factor in the appropriate row to obtain the actual gas
concentration. For example, if you are detecting pentane and the display reads 10%
LEL for the catalytic combustible channel, you actually have 10% LEL x 1.56 = 15.6%
LEL pentane present.
Table 4: GX-6000 Response Time vs. Sample Hose Length
Hose Used
Typical Time to 90% of
Response (T90)
Probe & 3 Foot Hose (standard)
10 seconds
Probe & 10 Foot Hose
15 seconds
Probe & 30 Foot Hose
30 seconds
Probe & 50 Foot Hose
40 seconds
