GDS-68XP Operation & Maintenance Manual, Revision 3.4
Page 22
SAMPLE EXHAUST
Changes in ambient pressure will affect the output from all electrochemical sensors, and allowing the
sample to exhaust directly to atmosphere will minimize these affects. Long runs of tubing connected to
the sample outlet may increase the backpressure inside the sensor flow cell and cause higher than normal
readings. Hydrogen sulfide is a heavy gas and will tend to ‘back up’ inside sample exhaust lines that
extend vertically for too great a distance.
Figure 5-8: GDS-68XP Exhaust Tubing
IMPORTANT
: DO NOT RESTRICT SAMPLE EXHAUST OUTLET. PRESSURE IN THE SAMPLE FLOW CELL MAY
DAMAGE THE SENSOR AND WILL RESULT IN INCORRECT READINGS.
IMPORTANT
: WHEN INSTALLING THE GDS-68XP OUTDOORS, MAKE SURE SAMPLE EXHAUST IS
PROTECTED BY A SCREEN OR FILTER TO KEEP INSECTS FROM ENTERING THE EXHAUST PORT AND NESTING
IN THE SENSOR FLOW CELL.
DANGER
: MAKE SURE EXHAUST GAS IS DIRECTED AWAY FROM PERSONNEL AND EQUIPMENT, ESPECIALLY
SUMPS OR LOW-LYING AREAS WHERE HEAVY GASES, SUCH AS HYDROGEN SULFIDE, CAN BUILD UP OVER
TIME.
HYDROGEN SULFIDE IS DEADLY AND EXPOSURE CAN RESULT IN INJURY OR DEATH.
Maximum Rise
Limit the vertical exhaust to
a point no greater than 15
feet above the top of the
GDS-68XP.
Sample Release to Atmosphere
Remember that sample exhaust is only released
to the atmosphere during sample measurement
time, not continuously
15’ / 5 m
maximum