Detcon 1000_H2S - Manual (Page 5)

Model 1000 H2S Echem
Model 1000 H2S Echem Instruction Manual Rev. 2.8 Page 1 of 30
1. Introduction
The Detcon Model 1000 Series H
2
S Process Analyzer is a 110/220VAC or 24VDC powered analyzer that
provides a select gas sample mixture to an on-board DM-624 H
2
S gas sensor assembly. The range of gas
analysis can span from 0-10ppm up to 0-5% (see Table 2 Sample Flow Rate). The range of analysis is
determined at time of order.
The NEMA 7X rating is achieved by housing all electronic components in suitable NEMA 7X enclosures.
When located outdoors, the H
2
S Process Analyzer package should be appropriately covered from direct
weather exposure. The Model 1000 Series H
2
S Process Analyzer can optionally be ordered with a full NEMA
4 enclosure.
The “Power Supply” explosion proof enclosure on the upper right side of the unit houses a 24VDC power
supply, a 24V DC-DC Converter, and a terminal PCB labeled for all input and output field wiring. The
“Pump/Flow” explosion proof enclosure located on the upper left houses an air dilution pump, an activated
carbon scrubber, and optional air flow fault and sample flow fault alarm PCB’s.
The analyzer requires a constant, liquid-free, 10±2psig sample pressure, which is provided by the customer or
may be supplied by Detcon as a separate gas sample handling system.
The on-board gas sample conditioning system includes a stainless steel pressure gauge (0-30psig), and a Genie
membrane filter to provide the analyzer with absolute condensate liquid protection. On the bypass port of the
Genie membrane filter, a 15 psig over-pressure relief valve and flow control valve are also provided. The flow
control valve can be used as a continuous sample bypass and liquid exhaust vent. A dedicated air and sample
mixture is maintained via 2 control valves and 2 rotameters. The Sample is then delivered to the Model DM-
624 H
2
S gas sensor for analysis. An optional on-board span gas cylinder is provided for span calibration, and
a selectable 3-way valve is provided for manually switching between sample monitoring and span calibrations.
An optional Acetic Acid Bubbler apparatus is available to scrub the gas sample when it contains high
concentrations of VOC’s as found in some injection spray H
2
S scavenger chemistries. An optional live heat
tracing feature may be used to prevent condensation after the Genie Membrane Filter.
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1.1 DM-624 Sensor
Figure 1 DM-624 Sensor