GDS-68XP Operation & Maintenance Manual, Revision 3.4
Page 14
SAMPLE DRAW CONFIGURATION
In addition to low and high positive pressure versions, the GDS-68XP can be configured to draw a sample
from ambient pressure sources. In this configuration the pump operates continuously to pull from both
purge air and sample sources (See Fig. 4-4).
Figure 4-4: GDS-68XP Flow Diagram (Sample Draw)
SENSOR CONSIDERATIONS
The GDS-68XP supports electrochemical sensors for hydrogen sulfide, THT and mercaptan. Each sensor
contains a fixed amount of chemical electrolyte that reacts with the target gas to create free electrons
that are amplified and measured. Once the electrolyte is depleted, sensor output will diminish and the
sensor must be replaced.
IMPORTANT:
TOXIC SENSORS ARE SUBJECT TO ACCELERATED DETERIORATION IF POWER IS NOT APPLIED
WITHIN 3 MONTHS OF SHIPMENT FROM GDS CORP.
Purge Air
Pump
Flow
Switch
Cal Gas Inlet
Sample
Inlet
Flow Meter
Sample Outlet
Sensor
Flow Cell
Run / Cal
Valve
3-Way
Valve
Purge Air
Inlet
Filter