Detcon P-1000 - Manual (Page 5)

P-1000
Portable Model 1000 H2S Analyzer Rev. 1.0 Page 1 of 24
1.0 Introduction
The Detcon Model P-1000 H
2
S Process Analyzer is a portable gas analyzer designed to provide accurate
measurement of Hydrogen Sulfide gas concentrations. The portable battery powered instrument utilizes
advanced electrochemical sensor technology and microprocessor based electronic control circuitry that
includes a built in data logger. Stored data can be downloaded to a spreadsheet and used to create trend
graphs. A universal signal conditioning circuit with an LCD display and the intelligent sensor module allow
several ranges of analysis that include 0-20ppm, 0-100ppm, and 0-1,000ppm. The analyzer sensor and control
circuitry are mounted in a weatherproof enclosure with a built in battery supply and sample conditioning
components. The Model P-1000-H
2
S is capable of continuous operation for a period of approximately 30 days
before battery recharge is required. A 12VDC Battery Charger/Power Source is supplied as part of the
standard equipment.
The analyzer requires a liquid-free, 5-10psig sample pressure, provided by the customer. The on-board gas
sample conditioning system includes a stainless steel pressure gauge (0-30psig), a Rotameter with flow valve,
and a Polycarbonate Coalescing Filter to provide the analyzer with condensing liquid protection. A 500cc/min
sample flow rate should be delivered to the Model 200 UniTox™ H
2
S Sensor for analysis. The H
2
S sample
flow is maintained by a control valve Rotameter. An Activated Carbon Scrubber is used to remove H
2
S prior
to venting. A 3-way valve provides for switching between sample monitoring and zero/span calibration.
1.1 UniTox™ Model 200 Description
The Detcon Model P-1000 H
2
S Process Analyzer is built around the UniTox™ Model 200 Series universal
toxic sensor. The Detcon UniTox™ Model 200 Series Sensors are non-intrusive “Smart” sensors designed to
detect and monitor for toxic gases in the parts per million (ppm) range. UniTox™ sensors operate as standard
two-wire 4-20mA loop-powered devices. Their intrinsically safe electronics design, when used with specified
intrinsically safe field wire barriers, conforms to a Class 1, Division 1, Group A, B, C, and D area
classifications.
The UniTox™ gas sensor consists of two major components: 1) the Universal Transmitter Module (UTM) and
2) the gas/range specific Intelligent Sensor Module (ISM). The universality of the design allows any ISM type
to be plugged into any UTM with seamless operation resulting. The ISM consists of an electrochemical toxic
gas sensor and associated PCB providing pre-amplifier, microprocessor, and memory storage functions.
Typical ranges of detection used in the P-1000 Analyzer are 0-20ppm, 0-100ppm and 0-1,000ppm. Other
ranges are available. All ranges are covered by this manual.
1.1.1 Sensor Technology
The sensors are electrolytic chemical cells. Each cell consists of three electrodes embedded in an electrolyte
solution all housed beneath a diffusion membrane. Sensitivity to specific target gases is achieved by varying
composition of any combination of the sensor components. The cells are diffusion limited via small capillary
barriers resulting in long service life of up to 3 or more years.
Figure 1 Construction of Electrochemical Cell