RKI Instruments EAGLE 2 Manual - Manual (Page 41)

EAGLE 2 Operator’s Manual Measuring Mode, Normal Operation • 31
The chart below illustrates how response time is affected by the sample hose
length.
Using Exhaust Tubing
The EAGLE 2’s exhaust fitting has a female 10-32 thread to allow for the
installation of a hose barb fitting with a 10-32 thread to which a flexible
exhaust tube can be connected. If you utilize this feature, the tubing used
must have a minimum internal diameter of 1/8 inch. RKI Instruments, Inc.
recommends using flexible polyurethane tubing with a maximum exhaust
tube length of 20 feet. Consult RKI Instruments, Inc. for exhaust tubing
lengths longer than 20 feet.
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 EAGLE 2 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 EAGLE 2 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 1.38 = 13.8% LEL
pentane present.
Table 4: EAGLE 2 Response Time vs. Sample Hose Length
Hose Used
Typical Time to 90%
of Response (T90)
Probe Only 12 seconds
Probe & 5 Foot Hose 15 seconds
Probe & 25 Foot Hose 25 seconds
Probe & 50 Foot Hose 35 seconds
Probe & 75 Foot Hose 45 seconds
Probe & 100 Foot Hose 60 seconds
Probe & 125 Foot Hose 75 seconds