OPERATION OF THE AREARAE
2-24
2.9 Integrated Sampling Pump
The AreaRAE includes an internal integrated sampling pump
with programmable high (400cc) and low (300cc) flow rate
settings.
A low pump speed of ~300cc per minute is the factory default
setting. This rate increases battery life by about 5%, which
results in an increased LEL sensor lifetime (See Section 4.7.9:
Change Pump Speed).
The high pump speed setting is required for vapors that are
especially reactive or easily absorbed by instrument surfaces.
Such vapors include, but are not limited to: Cl
2
, PH
3
, NH
3
,
HCN, and semi-volatile organic compounds like diesel fuel and
jet fuels. Here are some suggestions for monitoring such
compounds:
•
Remove the External Filter for normal calibration and
operation, which increases the pump speed to ~300 cc per
minute.
•
Use inert connecting or sampling tubing, such as Teflon
®
instead of Tygon
®
; make tube connections as short as
possible.
The pump automatically turns on when the monitor is turned
on. It remains on during normal operation.
If liquid or other substances are sucked into the External Filter
through the gas entry port, causing the pump to stall, the
electronics of the monitor immediately detect the obstruction
and shut down the pump. The alarm activates and you see the
flashing “Pump” error message. After the filter is changed or
obstacles are removed, press [Y/+] to restart the pump.
