Detcon 1000 User Manual

Detcon Model 1000

H2S Process Analyzer - Electrochemical Sensor

with Instrument Air

PART NO.
MODEL NO.
SERIAL NO.
INPUT VOLTAGE
FREQUENCY
CURRENT LOAD
AREA CLASSIFICATION

3200 A-1 Research Forest Dr.
The Woodlands, TX 77381

www.detcon.com

detcon inc.

AIR

INLET

AIR

FLOW

SAMPLE

SAMPLE

FLOW

SAMPLE PRESSURE
10 PSIG (CONSTANT)

INLET

Operator’s Installation and Instruction Manual

Detcon Model 1000 Series H2S Analyzer consists of two major assemblies:

1. The Model 1000 Series gas sample-conditioning assembly.

2. The Model DM-624 H

S gas sensor (using Alcohol Free - Electrochemical Sensor).

2

DETCON, Inc.

3200 Research Forest Dr.,

The Woodlands, Texas 77387

Ph.281.367.4100 / Fax [phone]

www.detcon.com

September 19, 2011 • Document # 3517 • Revision 1.1

Mdl 1000 H2S E-Chem / Inst. Air

Page intentionally blank

Model 1000 H2S E-Chem w Instrument Air ii

Mdl 1000 H2S E-Chem / Inst. Air

Table of Contents

1. Introduction.............................................................................................................................................. 1

1.1 DM-624 Sensor .................................................................................................................................... 1

1.2 Electrochemical Sensor ........................................................................................................................ 2

1.3 Microprocessor Control Circuit............................................................................................................ 2

1.4 Base Connector Board.......................................................................................................................... 3

1.5 Interference Data .................................................................................................................................. 4

1.6 Explosion Proof Enclosures ................................................................................................................. 4

2. Specifications............................................................................................................................................ 5

3. Installation................................................................................................................................................ 6

3.1 Mounting .............................................................................................................................................. 6

3.2 Gas Connections and Sampling System Notes..................................................................................... 6

3.3 Electrical Connections.......................................................................................................................... 7

3.4 Relays and RS-485 Setup ..................................................................................................................... 9

4. Start Up................................................................................................................................................... 11

5. Operating Software ............................................................................................................................... 12

5.1 Programming Magnet Operating Instructions .................................................................................... 12

5.2 Operating Software............................................................................................................................. 12

5.2.1 Normal Operation...................................................................................................................... 12

5.2.2 Calibration Mode....................................................................................................................... 13

5.2.3 Program Mode ........................................................................................................................... 13

5.2.4 Software Flow Chart.................................................................................................................. 14

6. Calibration and Maintenance............................................................................................................... 15

6.1.1 Zero Calibration......................................................................................................................... 15

6.1.2 Span Calibration........................................................................................................................ 15

7. Programming Alarms............................................................................................................................ 17

7.1 Alarm Reset........................................................................................................................................ 17

7.2 Other Alarm Functions....................................................................................................................... 17

8. Programming Features.......................................................................................................................... 18

9. RS-485 Protocol ..................................................................................................................................... 18

10. Display Contrast Adjustment............................................................................................................... 21

11. Low Flow Fault Options........................................................................................................................ 21

12. Sensor Replacement............................................................................................................................... 21

13. Troubleshooting..................................................................................................................................... 22

14. Spare Parts............................................................................................................................................. 23

15. Warranty................................................................................................................................................ 25

16. Flow Diagrams....................................................................................................................................... 26

17. Wiring Diagram..................................................................................................................................... 27

Appendix C....................................................................................................................................................... 28

Revision Log .................................................................................................................................................. 28

Model 1000 H2S E-Chem w Instrument Air iii

Mdl 1000 H2S E-Chem / Inst. Air

Table of Figures

Figure 1 DM624 Sensor ....................................................................................................................................... 1

Figure 2 Construction of Electrochemical Sensor................................................................................................ 2

Figure 3 Functional Block Diagram..................................................................................................................... 3

Figure 4 DM-624 Control Circuit......................................................................................................................... 3

Figure 5 Connector Board Terminals................................................................................................................... 3

Figure 6 Explosion proof enclosures.................................................................................................................... 4

Figure 7 Unit Dimensions .................................................................................................................................... 6

Figure 8 Port Identification .................................................................................................................................. 7

Figure 9 Installation Wiring Connections ............................................................................................................ 8

Figure 10 Alarm Jumpers..................................................................................................................................... 9

Figure 11 RS-485 Dip Switches......................................................................................................................... 10

Figure 12 Programming Magnet ........................................................................................................................ 12

Figure 13 DM-624 Software Flow Chart ........................................................................................................... 14

Figure 14 Analyzer Parts Identification ............................................................................................................. 23

Figure 15 DM-624 Replacement Parts............................................................................................................... 24

Figure 16 Unit Flow Diagram ............................................................................................................................ 26

Figure 17 Wiring Diagram ................................................................................................................................. 27

Shipping Address: 3200 A-1 Research Forest Dr., The Woodlands Texas 77381

Mailing Address: P.O. Box 8067, The Woodlands Texas 77387-8067

Phone: [phone] • Fax: [phone] •

Model 1000 H2S E-Chem w Instrument Air iv

www.detcon.com • [e-mail]

Mdl 1000 H2S E-Chem / Inst. Air

1. Introduction

The Detcon Model 1000 Series H
provides a select gas sample mixture to an on-board DM-624 H
analysis can span from 0-10ppm up to 0-20,000ppm (2%). 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
weather exposure. The Model 1000 Series H
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
“Flow” explosion proof enclosure located on the upper left houses the 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 DM­624 H

a selectable 3-way valve is provided for manually switching between sample monitoring and span calibrations.

®

S gas sensor for analysis. An optional on-board span gas cylinder is provided for span calibration, and

2

1.1 DM-624 Sensor

S Process Analyzer is a 110/220VAC or 24VDC powered analyzer that

2

S gas sensor assembly. The range of gas

2

S Process Analyzer package should be appropriately covered from direct

2

S Process Analyzer can optionally be ordered with a full NEMA

2

Figure 1 DM624 Sensor

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 1 of 28

Mdl 1000 H2S E-Chem / Inst. Air

Detcon MicroSafe™ Model DM-624, toxic sensors are non-intrusive “Smart” sensors designed to detect and
monitor for H

S gas in the ppm range. A primary feature of the sensor is its method of automatic calibration,

2

which guides the user through each step via instructions displayed on the backlit LCD. The sensor features
field adjustable, fully programmable alarms and provides relays for two alarms plus fault as standard. The
sensor comes with two different outputs: analog 4-20mA, and serial RS-485. These outputs allow for greater
flexibility in system integration and installation. The microprocessor-supervised electronics are packaged as a
plug-in module that mates to a standard connector board. Both are housed in an explosion proof condulet that
includes a glass lens window that allows for the display of sensor readings as well as access to the sensor’s

menu driven features via a hand-held programming magnet.

1.2 Electrochemical Sensor

The sensor is an electrochemical cell. 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. Good specificity is achieved in each sensor type.
The cell is diffusion limited via small capillary barriers resulting in long service life of up to 3 or more years
depending on the application.

NOTE: This particular sensor cell is unique in that it has no cross-sensitivity to alcohol vapors

and thus is a good choice for measuring H

S in natural gas pipelines.

2

Figure 2 Construction of Electrochemical Sensor

DM-624 Electrochemical Sensor Principle of Operation

Method of detection is by an electrochemical reaction at the surface of an electrode called the sensing
electrode. Air and gas diffuse through the stainless steel filter and the capillary diffusion barrier. The
controlling circuit maintains a small external operating voltage between the sensing and counter electrodes of
the proper bias and magnitude so that no current flows to or from the reference electrode while its potential is
maintained at the correct fixed voltage — usually ground. The electrochemical reaction creates a change in
current flow from the counter electrode to the sensing electrode. This change in current is proportional to the
gas concentration and is reversible. The quick response of the sensor results in continuous monitoring of
sample gas conditions.

1.3 Microprocessor Control Circuit

The control circuit is microprocessor based, and is packaged as a plug-in field replaceable module, facilitating
easy replacement and minimum down time. Circuit functions include a basic sensor pre-amplifier, on-board
power supplies, microprocessor, back lit alpha numeric display, alarm status LED indicators, magnetic
programming switches, an RS-485 communication port, and a linear 4-20mA DC output.

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 2 of 28

Mdl 1000 H2S E-Chem / Inst. Air

Figure 3 Functional Block Diagram

Figure 4 DM-624 Control Circuit

1.4 Base Connector Board

The base connector board is mounted in the explosion proof enclosure and includes: the mating connector for
the control circuit, reverse input and secondary transient suppression, input filter, alarm relays, lug less
terminals for all field wiring, and a terminal strip for storing unused programming jumper tabs. The alarm
relays are contact rated 5 amps @ 250VAC, 5 amps @ 30VDC and coil rated at 24VDC. Gold plated program
jumpers are used to select either the normally open or normally closed relay contacts.

Figure 5 Connector Board Terminals

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 3 of 28

Mdl 1000 H2S E-Chem / Inst. Air

1.5 Interference Data

DM-624 series electrochemical H

S sensors are subject to interference from other gases. This interaction is

2

shown in the following table as the relation between the amount of the interfering gas applied to the sensor,
and the corresponding reading that will occur (in ppm).

Gas Interference

Carbon monoxide 300ppm ≤1.5ppm
Chlorine 1ppm = -0.2ppm
Ethyl mercaptan 3ppm = 1ppm
Ethylene 100ppm = 0
Hydrogen 1% = < 5ppm
Hydrogen chloride 5ppm = 0
Hydrogen cyanide 10ppm = 0
Nitric oxide 35ppm < 2ppm
Nitrogen dioxide 5ppm = -0.5ppm
Sulfur dioxide 5ppm < 1ppm
Methyl mercaptan 2ppm = 1ppm

1.6 Explosion Proof Enclosures

The sensor is packaged in a cast metal explosion proof enclosure. The enclosure is fitted with a threaded cover
that has a glass lens window. Magnetic program switches located behind the transmitter module faceplate are
activated through the lens window via a hand-held magnetic programming tool allowing non-intrusive
operator interface with the sensor. All calibration and alarm level adjustments can be accomplished without
removing the cover or declassifying the area. Electrical classification is Class I; Div. 1; Groups C, D.

Flow Fault (optional)

Pump/Scrubber

Power Supply/

Terminal PCB

Sensor (side view)

Sensor

+

+

24VDC

18-36

OUT

VDC

2.1A

IN

Left

Right

Figure 6 Explosion proof enclosures

A 24VDC power supply and termination PCB for the power, relay contacts, 4-20mA output, and/or RS485
signal, are located in the upper right explosion proof enclosure. The pump and optional low flow fault

assemblies are located in the upper left explosion proof enclosure. Declassify the work area before removing

covers.

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 4 of 28

Mdl 1000 H2S E-Chem / Inst. Air

2. Specifications

Sensor Type

Electrochemical cell

Measurement Range

0-10ppm H

Accuracy/Repeatability

±10% of reading or ±0.5ppm, whichever is greater

Response/Clearing Time

T80 < 1 minute

Operating Temperature

-40°F to +122°F: -40°C to +50°C

Outputs

Linear 4-20mA DC; RS-485 Modbus™; 3 relays (alarm 1, alarm 2, and fault), Contacts rated 5 amps

Input Voltage

110~220VAC; 10~30VDC

Power Consumption

700mA (16.8 watts)

Electrical Classification

Explosion Proof; Class I, Division 1, Groups C, D

Sensor Life/Warranty

Sensor: 6 month conditional warranty; Transmitter: 2 year warranty

Analyzer Weight

70 lbs.

Dimensions

29” X 29” X 8”

S, up to 0-10,000ppm H2S

2

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 5 of 28

Mdl 1000 H2S E-Chem / Inst. Air

3. Installation

3.1 Mounting

Securely mount the Model 1000 analyzer panel or NEMA 4 enclosure (optional) in accordance with

Figure 7.

Figure 7 Unit Dimensions

3.2 Gas Connections and Sampling System Notes

1. Install a length of tubing from the desired sample point to the sample input port (as shown in

Sample draw tubing should be 316 stainless steel of ¼" O.D.

NOTE: A constant pressure of 10±2psig should be provided to the analyzer for proper operation. In

applications where line pressure varies significantly, two-stage pressure regulation is recommended to
hold the constant pressure. Ideally, the pressure drop from the source to 10psig for analyzer should be
taken as close to the pipeline as possible. This speeds up response time to actual gas concentration
changes. An insertion probe membrane device is advisable to use for pipeline sources with high levels
of condensates, mist, and contamination.

Figure 8.

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 6 of 28

Mdl 1000 H2S E-Chem / Inst. Air

PART NO.

MODEL NO.
SERIAL NO.
INPUT VOLTAGE
FREQUENCY
CURRENT LOAD
AREA CLASSIFICATION

3200 A-1 Research Forest Dr.
The Woodlands, TX 77381

www.detcon.com

detcon inc.

AIR

Instrument Air Inlet Port

Pressure Gauge

Sample Inlet Port

INLET

SAMPLE

FLOW

AIR

FLOW

Cal Gas

SAMPLE PRESSURE
10 PSIG (CONSTANT)

SAMPLE

INLET

NOTE:

These may be

combined into a

single vent

Sample

Sample Bypass and Liquid
Rejection Exhaust Vent.

Over Pressure Relief Vent

Calibrate

H

2S Vent

Figure 8 Port Identification

2. Supply Instrument Air to the “Air Inlet” port (

Figure 8). The instrument air should be regulated to

10±1psig.

3. Whenever possible, the Sample Bypass flow control valve of the Genie membrane filter should be used to

minimize the sample lag time between the sample tap and the analyzer location. It can also be used as a
means to exhaust condensed liquids in the sample line away from the Genie filter and prevent a “loss of
flow” condition. Set a flow of 100-200cc/min. and vent to a safe area using ¼” O.D. tubing.

4. Connect to the Over-pressure Relief valve and vent to a safe area. The pressure relief valve is set at

Detcon to open at 15-20psig. For convenience sake, the sample bypass and over-pressure relief can be
vented together.

5. Install a length of ¼" OD stainless steel tubing from the vent port to an area deemed safe for venting as

shown in

Figure 8. Venting pressure should be in the range of 0±1psig and ambient pressure is highly

preferred.

3.3 Electrical Connections

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 7 of 28

Mdl 1000 H2S E-Chem / Inst. Air

Customer Connections

INPUT

++

++

24VDC

24VDC

OUT

OUT

2.1A

2.1A

18-36

18-36

VDC

VDC

IN

IN

+24VDC

+

-24VDC

-

(Ground)

++

24VDC

18-36

OUT

VDC

2.1A

IN

AIR

SAMPLE

FLOW

FLOW

117VAC / 24VDC In
4-20mA, RS485,

Alarm/Fault Sensor Relays
Low Flow Air/ Sample Relays
(Optional)

Figure 9 Installation Wiring Connections

1. For AC powered unit connect 117/220VAC to the terminal connector labeled “VAC IN” (JP8A) inside the

explosion-proof enclosure on the upper right. If applicable, connect 24VDC to the Terminal Connector
Board labeled “VDC IN” (JP7A). (

Figure 9)

2. The 4-20mA and/or RS-485 signal outputs should be wired from the terminal PCB and then out the right

side of the “Power Supply” explosion-proof enclosure. (

Figure 9).

3. Discrete alarm relay contacts are provided for three alarms: Fault, Low and High. The contacts consist of

common and choice of normally open or normally closed. Contact output selections are jumper
programmable on the sensor connector board. See DM-624 wiring diagram for details. These connections
also should be wired out of the right side of the “Power Supply” explosion-proof enclosure. (

Figure 9).

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 8 of 28

Mdl 1000 H2S E-Chem / Inst. Air

4. Optional Low Flow Fault Alarm PCA’s for Sample gas and Air are available. They provide a form “C”

relay contact (common, normally open and normally closed) rated 1 amp at 30VDC/0.24 amp at 125VAC.
Relay contacts are pre-wired to the I/O connector PCB located in the “Power Supply” explosion-proof
enclosure and are labeled “FLO FLT1” and “FLO FLT2” respectively (

Figure 9).

3.4 Relays and RS-485 Setup

Program the alarms via the gold plated jumper tab positions located on the CPU board (
and Alarm 2 have three jumper programmable functions: latching/non-latching relays, normally
energized/normally de-energized relays, and ascending/descending alarm set points. The fault alarm has two
jumper programmable functions: latching/non-latching relay, and normally energized/normally de-energized
relay. The default settings of the alarms (jumpers removed) are normally de-energized relays, non-latching
relays, and alarm points that activate during descending gas conditions.

Figure 10). Alarm 1

Figure 10 Alarm Jumpers

If a jumper tab is installed in the latch position that alarm relay will be in the latching mode. The latching
mode will latch the alarm after alarm conditions have cleared until the alarm reset function is activated. The
non-latching mode (jumper removed) will allow alarms to de-activate automatically once alarm conditions
have cleared.

If a jumper tab is installed in the energize position, that alarm relay will be in the energized mode. The
energized mode will energize or activate the alarm relay when there is no alarm condition and de-energize or
de-activate the alarm relay when there is an alarm condition. The de-energized mode (jumper removed) will
energize or activate the alarm relay during an alarm condition and de-energize or de-activate the alarm relay
when there is no alarm condition.

If a jumper tab is installed in the ascending position that alarm relay will be in the ascending mode. The
ascending mode will cause an alarm to fire when the gas concentration detected is greater than or equal to the
alarm set point. The descending mode (jumper removed) will cause an alarm to fire when the gas
concentration detected is lesser than or equal to the alarm set point. Except in special applications, H

S

2

monitoring will require alarms to fire in “ASCENDING” gas conditions.

Any unused jumper tabs should be stored on the connector board on the terminal strip labeled “Unused
Jumpers”.

If applicable, set the RS-485 ID number via the two rotary dip switches located on the preamp board (see
Figure 11). There are 256 different ID numbers available, which are based on the hexadecimal numbering
system. If RS-485 communications are used, each sensor must have its own unique ID number. Use a
jeweler’s screwdriver to set the rotary dipswitches according to

Table 1 Hexadecimal Conversion. If RS-485

communications are not used, leave the dipswitches in the default position, which is zero/zero (0)-(0).

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 9 of 28

Mdl 1000 H2S E-Chem / Inst. Air

Replace the plug-in control circuit and replace the junction box cover.

Table 1 Hexadecimal Conversion

ID# SW1 SW2 ID# SW1 SW2 ID# SW1 SW2 ID# SW1 SW2 ID# SW1 SW2 ID# SW1 SW2

none

0 0 43 2 B 86 5 6 129 8 1 172 A C 215 D 7
1 0 1 44 2 C 87 5 7 130 8 2 173 A D 216 D 8
2 0 2 45 2 D 88 5 8 131 8 3 174 A E 217 D 9
3 0 3 46 2 E 89 5 9 132 8 4 175 A F 218 D A
4 0 4 47 2 F 90 5 A 133 8 5 176 B 0 219 D B
5 0 5 48 3 0 91 5 B 134 8 6 177 B 1 220 D C
6 0 6 49 3 1 92 5 C 135 8 7 178 B 2 221 D D
7 0 7 50 3 2 93 5 D 136 8 8 179 B 3 222 D E
8 0 8 51 3 3 94 5 E 137 8 9 180 B 4 223 E F
9 0 9 52 3 4 95 5 F 138 8 A 181 B 5 224 E 0

10 0 A 53 3 5 96 6 0 139 8 B 182 B 6 225 E 1
11 0 B 54 3 6 97 6 1 140 8 C 183 B 7 226 E 2
12 0 C 55 3 7 98 6 2 141 8 D 184 B 8 227 E 3
13 0 D 56 3 8 99 6 3 142 8 E 185 B 9 228 E 4
14 0 E 57 3 9 100 6 4 143 8 F 186 B A 229 E 5
15 0 F 58 3 A 101 6 5 144 9 0 187 B B 230 E 6
16 1 0 59 3 B 102 6 6 145 9 1 188 B C 231 E 7
17 1 1 60 3 C 103 6 7 146 9 2 189 B D 232 E 8
18 1 2 61 3 D 104 6 8 147 9 3 190 B E 233 E 9
19 1 3 62 3 E 105 6 9 148 9 4 191 B F 234 E A
20 1 4 63 3 F 106 6 A 149 9 5 192 C 0 235 E B
21 1 5 64 4 0 107 6 B 150 9 6 193 C 1 236 E C
22 1 6 65 4 1 108 6 C 151 9 7 194 C 2 237 E D
23 1 7 66 4 2 109 6 D 152 9 8 195 C 3 238 E E
24 1 8 67 4 3 110 6 E 153 9 9 196 C 4 239 F F
25 1 9 68 4 4 111 6 F 154 9 A 197 C 5 240 F 0
26 1 A 69 4 5 112 7 0 155 9 B 198 C 6 241 F 1
27 1 B 70 4 6 113 7 1 156 9 C 199 C 7 242 F 2
28 1 C 71 4 7 114 7 2 157 9 D 200 C 8 243 F 3
29 1 D 72 4 8 115 7 3 158 9 E 201 C 9 244 F 4
30 1 E 73 4 9 116 7 4 159 9 F 202 C A 245 F 5
31 1 F 74 4 A 117 7 5 160 A 0 203 C B 246 F 6
32 2 0 75 4 B 118 7 6 161 A 1 204 C C 247 F 7
33 2 1 76 4 C 119 7 7 162 A 2 205 C D 248 F 8
34 2 2 77 4 D 120 7 8 163 A 3 206 C E 249 F 9
35 2 3 78 4 E 121 7 9 164 A 4 207 C F 250 F A
36 2 4 79 4 F 122 7 A 165 A 5 208 D 0 251 F B
37 2 5 80 5 0 123 7 B 166 A 6 209 D 1 252 F C
38 2 6 81 5 1 124 7 C 167 A 7 210 D 2 253 F D
39 2 7 82 5 2 125 7 D 168 A 8 211 D 3 254 F E
40 2 8 83 5 3 126 7 E 169 A 9 212 D 4 255 F F
41 2 9 84 5 4 127 7 F 170 A A 213 D 5
42 2 A 85 5 5 128 8 0 171 A B 214 D 6

Figure 11 RS-485 Dip Switches

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 10 of 28

Mdl 1000 H2S E-Chem / Inst. Air

4. Start Up

Upon completion of all tubing connections and field wiring the Model 1000 Series Process Analyzer is ready
for startup. Note that after power is applied, varying readings may occur during sensor warm-up. Allow at
least 1 hour for stabilization (24 hours is best). With sample gas and air flowing, apply system power and
observe the following normal conditions:

a) DM-624 “Fault” LED’s are off.
b) A reading close to the anticipated H

up” cycle.

NOTE: All alarms will be disabled for 1 minute after power up. In the event of power failure,

the alarm disable period will begin again once power has been restored.

1. Set the sample pressure to 10psig and verify the proper set point at the pressure gauge.

2. Assure that the Instrument Air is set to 10psig at the input to the Air Inlet Port.

3. Set the airflow through the Air Flow Rotameter. Adjust the Rotameter Airflow valve to the value noted in

Table 2 (Air Flow Column) and in alignment with the “→” mark on the Rotameter.

NOTE: Sample flow rates must be actual Rotameter set-point flow rates, after properly

accounting for Rotameter gas density effects, see

S level should be indicated upon conclusion of a 1-minute “warming

2

Table 2.

Table 2 Sample Flow Rate

DM-624 Range

(ppm)

0-10
0-20
0-25

0-50
0-100
0-150
0-500

0-5000

0-10,000

0-2%

Sample Flow

(cc/min)
200 Labeled “S→”
200 Labeled “S→”
200 Labeled “S→”
200 Labeled “S→”
200 Labeled “S→”
200 Labeled “S→”

80 Labeled “S→”

200 Labeled “S→”

80 Labeled “S→”

200 Labeled “S→”

Air Flow

(cc/min)

500
500
500
500
500
500

1000

800
800
750

Span Gas Flow

(cc/min)
250 Labeled “C→”
250 Labeled “C→”
250 Labeled “C→”
250 Labeled “C→”
250 Labeled “C→”
250 Labeled “C→”
100 Labeled “C→”
250 Labeled “C→”
100 Labeled “C→”
250 Labeled “C→”

H2S Cal Gas

(ppm)

10
10

10
10 or 25
25 or 50
25 or 50

100
1,000 or 2,500
2,500 or 5,000

5,000

4. Adjust the sample mass flow controller valve per

Table 2 to meet the designated sample flow target mark
labeled as “S→”. The “C→” indicator on the Rotameter shows what Flow rate to calibrate at if the cal gas
is N

. If the cal gas is in methane, then span gas flow should be set to “S→”.

2

NOTE: A displayed methane (typical natural gas) sample flow of 200cc/min. is actually equal

to 250cc/min. of nitrogen when accounting for the 20% gas density affect on the Rotameter. A
displayed methane flow of 80cc/min. is actually 100cc/min. when accounting for the density
effect.

5. Set the Airflow Rotameter per the Air Flow value in

Table 2 that corresponds to the DM-624 Sensor

Range.

6. Proceed with calibration per Section

6 Calibration and Maintenance.

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 11 of 28

Mdl 1000 H2S E-Chem / Inst. Air

5. Operating Software

5.1 Programming Magnet Operating Instructions

Operator interface to MicroSafe™ gas detection products is via magnetic switches located behind the

transmitter faceplate. DO NOT remove the glass lens cover to calibrate or change programming parameters.

Two switches labeled “PGM 1” and “PGM 2” allow for complete calibration and alarm level programming
without removing the enclosure cover, thereby eliminating the need for area de-classification or the use of hot
permits.

Figure 12 Programming Magnet

A magnetic programming tool (
momentary contact, 3-second hold, and 30-second hold. In momentary contact use, the programming magnet
is waved over a switch location. In 3-second hold, the programming magnet is held in place over a switch
location for 3 or more seconds. In 30-second hold, the programming magnet is held in place over a switch
location for 30 or more seconds. Three and 30-second hold is used to enter or exit calibration and program
menus while momentary contact is used to make adjustments. The location of “PGM 1” and “PGM 2” are
shown in section

NOTE: If, after entering the calibration or program menus, there is no interaction with the

menu items for more than 30 seconds, the sensor will return to its normal operating condition.

1.3.

5.2 Operating Software

Operating software is menu listed with operator interface via the two magnetic program switches located under
the faceplate. The two switches are referred to as “PGM 1” and “PGM 2”. The menu list consists of 3 items
which include submenus as indicated below.

01. Normal Operation
a) Current Status

02. Calibration Mode
a) Zero
b) Span

03. Program Menu
a) Program Status
b) Alarm 1 Level
c) Alarm 2 Level
d) Calibration Level

5.2.1 Normal Operation

In normal operation, the display tracks the status of the sensor and gas concentration and appears as: “##.##
PPM H2S”. The milliamp current output corresponds to the monitoring level and range of the sensor, where

Full Scale is 20mA.

Figure 12) is used to operate the switches. Switch action is defined as

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 12 of 28

Mdl 1000 H2S E-Chem / Inst. Air

5.2.2 Calibration Mode

Calibration mode allows for sensor zero and span adjustments. It uses an “AUTO SPAN” sequence with built
in diagnostics to ensure adequate sensor response and signal stability. “1-ZERO 2-SPAN”

Zero Adjustment

Zero is set with no H

S target gases present. “AUTO ZERO”

2

Span Adjustment

Span adjustment is performed with a target gas concentration of 10 ppm H

concentrations other than 10 ppm may be used. “AUTO SPAN” See

Table 3 Sample Flow Rate

S in nitrogen. Span gas

2

5.2.3 Program Mode

Program Mode provides a program status menu (View Program Status) to check operational parameters.
Program Mode also allows for the adjustment of alarm set point levels, the calibration gas level setting,

View Program Status

View Program Status is a listing that allows the operator to view the gas, range, and software version number
of the program, as well as the current alarm settings, calibration gas level setting, offset value, RS-485 ID
number, heater voltage, and estimated remaining sensor life.

The following procedure is used to view the programming status of the sensor:

a) Enter the programming menu by holding the programming magnet stationary over “PGM 2” for 15

seconds. When the display changes to “VIEW PROG STATUS”, withdraw the magnet. Scroll through

the programming menu by momentarily waving the programming magnet over either “PGM 1” or “PGM
2”. The menu options are: View Program Status, Set Alarm 1 Level, Set Alarm 2 Level, and Set Cal
Level.

b) Scroll to the “VIEW PROG STATUS” listing and hold the programming magnet over “PGM 1” for 3

seconds. The display will automatically scroll, at five second intervals, through the following information

before returning back to the “VIEW PROG STATUS” listing.

¾ Gas type and software version number.
¾ Alarm set point level of alarm 1. The menu item appears as: “ALM1 SET @ ##PPM”
¾ Alarm firing direction of alarm 1. The menu item appears as: “ALM1 ASCENDING” or descending.
¾ Alarm relay latch mode of alarm 1. The menu item appears as: “ALM1 NONLATCHING” or latching.
¾ Alarm relay energize state of alarm 1. The menu item appears as: “ALM1 DE-ENERGIZED” or

energized.

¾ Alarm set point level of alarm 2. The menu item appears as: “ALM2 SET @ ##PPM”
¾ Alarm firing direction of alarm 2. The menu item appears as: “ALM2 ASCENDING” or descending.
¾ Alarm relay latch mode of alarm 2. The menu item appears as: “ALM2 LATCHING” or non-latching.
¾ Alarm relay energize state of alarm 2. The menu item appears as: “ALM2 DE-ENERGIZED” or

energized.

¾ Alarm relay latch mode of the fault alarm. The menu item appears as: “FLT NONLATCHING” or

latching.

¾ Alarm relay energize state of the fault alarm. The menu item appears as: “FLT ENERGIZED” or de-

energized.

¾ Calibration gas level setting. The menu item appears as: “CAL LEVEL @ ##PPM”

Identification of the RS-485 ID number setting. The menu item appears as: “485 ID SET @ ##”

¾

¾ Estimated remaining sensor life. The menu item appears as: “SENSOR LIFE 100%”

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 13 of 28

Mdl 1000 H2S E-Chem / Inst. Air

c) Exit back to normal operations by holding the programming magnet over “PGM 2” for 3 seconds, or, the

sensor will automatically return to normal operation in 30 seconds.

Alarm 1 Level Adjustment

The alarm 1 level is adjustable over the range 10% to 90% of range. For hydrogen sulfide gas sensors, the

level is factory set at 20% F.S. The menu item appears as: “SET ALM1 @ ### PPM”.

Alarm 2 Level Adjustment

The alarm 2 level is also adjustable over the range 10% to 90% of range. For hydrogen sulfide gas sensors, the

level is factory set at 60 % Full Scale. The menu item appears as: “SET ALM2 @ ### PPM”

Calibration Level Adjustment
The Calibration level is adjustable from 10% to 90% of range. The menu item appears as: “CAL LEVEL @

## PPM”

5.2.4 Software Flow Chart

Figure 13 DM-624 Software Flow Chart

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 14 of 28

Mdl 1000 H2S E-Chem / Inst. Air

6. Calibration and Maintenance

The Model 1000 Series H2S Process Analyzer is calibrated prior to shipment. Only minimal adjustment
should be required at time of commissioning. However, it is highly recommended that a zero and span
calibration be performed twice in the first week of operation to assure optimum system performance. After
that, a recalibration interval of every month is recommended.

Maintenance

When the Acetic Acid Bubbler option is used, the 5% acetic acid solution (or white vinegar) should be kept
near the Max fill mark on the bottle. The level should be checked monthly and the entire solution contents
should be changed every 6 months.

Material Requirements

9 Detcon Part Number 327-000000-000 MicroSafe™ Programming Magnet.

9 Detcon Part Number 942-001123-000 Zero Air cal gas. (Ambient air can be used, if it can be verified that

no target gas is present).

9 Span gas cylinder containing H

available, span gas cylinders in background Methane (natural gas) or air can also be used.

6.1.1 Zero Calibration

Zero Calibration should be performed quarterly in the field. The AutoZero function is used to zero the sensor.
The dilution airflow (with sample turned off) can be used to zero calibrate the sensor. Alternately, a zero air or
N

cylinder connected to the calibration port can be used.

2

1) Turn the sample flow mass control off, leaving only the airflow to provide the zero gas. Allow the unit 5

minutes to stabilize.

2) Enter the calibration menu by holding the programming magnet stationary over “PGM 1” (see above) for 3

seconds until the display reads “1-ZERO 2-SPAN”, and remove the magnet. Note that the “CAL” LED

comes on.

3) Enter the zero menu by holding the magnet stationary over “PGM 1” for 3 seconds until the display reads:

“AUTOZERO”, and remove the magnet. The sensor will enter the auto zero mode. When complete the
sensor will display “ZERO COMPLETE” for 5 seconds and then return to the normal operation menu,
“0.00PPM H2S”.

4) Re-open the sample flow mass control and re-establish the target sample flow rate per the arrow indicator

on the H

S sample Rotameter.

2

6.1.2 Span Calibration

S gas in background N2 (nitrogen) as per the following range table. If

2

Table 3 Sample Flow Rate

DM-624 Range

(ppm)

0-10
0-20
0-25

0-50
0-100
0-150
0-500

0-5000

0-10,000

0-2%

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 15 of 28

Sample Flow

(cc/min)

200 Labeled “S→”
200 Labeled “S→”
200 Labeled “S→”
200 Labeled “S→”
200 Labeled “S→”
200 Labeled “S→”

80 Labeled “S→”

200 Labeled “S→”

80 Labeled “S→”

200 Labeled “S→”

Air Flow

(cc/min)

500
500
500
500
500
500

1000

800
800
750

Span Gas Flow

(cc/min)

250 Labeled “C→”
250 Labeled “C→”
250 Labeled “C→”
250 Labeled “C→”
250 Labeled “C→”
250 Labeled “C→”
100 Labeled “C→”
250 Labeled “C→”
100 Labeled “C→”
250 Labeled “C→”

H2S Cal Gas

(ppm)

10
10

10
10 or 25
25 or 50
25 or 50

100

1000 or 2500

2,500 or 5,000

5,000

Mdl 1000 H2S E-Chem / Inst. Air

CAUTION: Verification of the correct calibration gas level setting and calibration span gas

concentration is required before “span” calibration. These two numbers must be equal.

Span Calibration consists of entering the calibration function and following the menu-displayed instructions.
The display will ask for the application of span gas in a specific concentration. The concentration must be
equal to the calibration gas level setting. See

Table 3 (Sample Flow Rate) for recommended cal gas
concentrations. Other concentrations may be used as long as they fall between 10% and 90% of range.
However, any alternate span gas concentration value must be programmed via the calibration gas level menu
before proceeding with span calibration. Follow the instructions below for span calibration.

1) Verify that the current calibration gas level is equal to the calibration span gas concentration. (Refer to

Section

2) If the calibration gas level setting is equal to the calibration span gas concentration, proceed to item “

5.2.3 Program Mode, “View Sensor Status”. The item appears as “CAL LEVEL @ ### PPM”.)

3)”.
If the calibration gas level setting is not equal to the calibration span gas concentration, adjust the
calibration gas level setting so that it is equal to the calibration span gas concentration.

a) Enter the programming menu by holding the programming magnet stationary over “PGM 2” for 30

seconds. When the display reads “VIEW PROG STATUS”, withdraw the magnet. Scroll through

the programming menu by momentarily waving the programming magnet over “PGM 1” or “PGM 2”.
The menu options are: View Program Status, Set Alarm 1 Level, Set Alarm 2 Level, Set Heater Level,
and Linearize Sensor.

b) From the programming menu scroll to the calibration level listing. The menu item appears as: “SET

CAL LEVEL”. Enter the menu by holding the programming magnet stationary over “PGM 1” for 3
seconds until the display reads “CAL LEVEL @ ### PPM”, and withdraw the magnet. Use the

programming magnet to increase (PGM 1) or decrease (PGM 2) the display reading until the reading is
equal to the desired calibration span gas concentration.

c) Exit to the programming menu by holding the programming magnet over “PGM1” for 3 seconds.
d) Exit back to normal operation by holding the programming magnet over “PGM 2” for 3 seconds, or,

the sensor will automatically return to normal operation in 30 seconds.

3) Enter the calibration span menu by holding the programming magnet stationary over “PGM 1” for 3

seconds. The display will read “1-SPAN 2-EXIT”. Hold programming magnet stationary over “PGM 1”
for 3 seconds to proceed with span. “APPLY ## PPM” will appear in the display for 10 seconds.

4) Turn the H

being drawn from the H

S 3-way valve so that the arrow is pointing toward the cal gas source. The sample is now

2

S Calibration Port.

2

5) Turn the fixed flow regulator on the Cal Gas Bottle to the “ON” position, and set the sample rotameter

mass flow valve so the flow is set to “C” on the Rotameter. The airflow should be set per the Air Flow
table. (See

Table 3 for these values).

6) As the sensor signal changes, the display will change to “AUTOSPAN ###”. Where “###” indicates the

actual gas reading. The reading will increase/decrease until the sensor stabilizes. When the sensor signal

is stable, the sensor will auto span to the requested concentration and the display will change to “SPAN
COMPLETE” for two seconds and then “REMOVE GAS” for 3 seconds. The analyzer will then return

to normal operation. The Auto Span sequence takes approximately 5 minutes.

7) Turn the fixed flow regulator on the Cal Gas Bottle to the “OFF” position and remove the gas.

NOTE: If the circuitry is unable to adjust the span to the proper setting the sensor will enter

into the calibration fault mode which will cause the display to alternate between the sensor’s

current status reading and the calibration fault display: “CAL FAULT”.

8) Turn the 3-way valve so that the arrow is pointing toward the sample source. Establish the target sample

gas flow through the sample Rotameter adjusting the flow rate to the “S” reading. Set the air Rotameter
per

Table 3 (Air Flow column) and the appropriate H2S gas range for the analyzer.

Span calibration is complete. The total time for span calibration is approximately 10 minutes.

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 16 of 28

Mdl 1000 H2S E-Chem / Inst. Air

Additional Notes

a) Upon entering the calibration menu, the 4-20mA signal drops to 2mA and is held at this level until the

sensor returns to normal operation.

b) If during calibration the sensor circuitry is unable to attain the proper adjustment for span, the sensor will

enter into the calibration fault mode which will activate fault alarm functions and cause the display to
alternate between the sensor’s current status reading and the calibration fault screen which appears as:

“CAL FAULT”. If this occurs, attempt to recalibrate by re-entering the calibration menu. If the sensor

fails again, refer to Section

c) After span calibration, the alarm relays remain inactive until the sample gas concentration falls below both

set alarm levels. The alarms will then become active again.

13 Troubleshooting

7. Programming Alarms

Both alarm 1 and alarm 2 levels are factory set prior to shipment. Alarm 1 is set at 20% of full-scale range;
alarm 2 at 40% of full-scale range. Both alarms can be set from 10 to 90% of full-scale range. The following
procedure is used to change alarm set points:

a) Enter the programming menu by holding the programming magnet stationary over “PGM 2” for 30

seconds until the display reads “VIEW PROG STATUS”, and withdraw the magnet. Scroll through the

programming menu by momentarily waving the programming magnet over “PGM 1” or “PGM 2”. The
menu options are: View Program Status, Set Alarm 1 Level, Set Alarm 2 Level, and Set Cal Level.

b) ALARM 1 LEVEL

appears as: “SET ALARM 1 LEVEL”. Enter the menu by holding the programming magnet stationary

over “PGM 1” for 3 seconds until the display reads “SET ALM1 @ ###PPM”, and withdraw the magnet.

Use the programming magnet to adjust the display reading using “PGM 1” to increase or “PGM 2” to
decrease the reading until the desired alarm set point is reached. Exit to the programming menu by
holding the programming magnet over “PGM1” for 3 seconds.

c) ALARM 2 LEVEL

appears as: “SET ALARM 2 LEVEL”. Enter the menu by holding the programming magnet stationary
over “PGM 1” for 3 seconds until the display reads “SET ALM2 @ ###PPM”, and withdraw the magnet.

Use the programming magnet to adjust the display reading using “PGM 1” to increase or “PGM 2” to
decrease the reading until the desired alarm set point is reached. Exit to the programming menu by
holding the programming magnet over “PGM1” for 3 seconds.

d) Exit back to normal operations by holding the programming magnet over “PGM 2” for 3 seconds, or, the

sensor will automatically return to normal operation in 30 seconds.

7.1 Alarm Reset

An alarm condition will cause the applicable alarm to activate its corresponding relay and LED. If alarm 1,
alarm 2, or fault alarms have been programmed for latching relays, an alarm-reset function must be activated
to reset the alarms after an alarm condition has cleared. To reset the alarms, simply wave the programming
magnet over either “PGM 1” or “PGM 2”, momentarily, while in normal operations mode and note that the
corresponding alarm LED(s) turn off.

7.2 Other Alarm Functions

Alarms are factory programmed to be non-latching, de-energized; and to fire under ascending gas conditions.
The fault alarm relay is programmed as normally energized which is useful for detecting a 24VDC power
source failure. All alarm functions are programmable via jumper tabs. Changing alarm functions requires the
sensor housing to be opened, thus declassification of the area is required.

: From the programming menu scroll to the alarm 1 level listing. The menu item

: From the programming menu scroll to the alarm 2 level listing. The menu item

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 17 of 28

Mdl 1000 H2S E-Chem / Inst. Air

8. Programming Features

Detcon MicroSafe™ H
interface and fail-safe operation. Program features are detailed in this section. Each sensor is factory tested,
programmed, and calibrated prior to shipment.

Over Range

When the sensor detects gas greater than 100% of its range, it will cause the display to flash the highest
reading of its range on and off.

Under Range Faults

If the sensor should drift below the zero baseline by approximately 10% of range, the display will indicate a

fault: “ZERO FAULT”. If the sensor drifts below the normal zero baseline by approximately -30% of range,
the display will indicate a “SIGNAL FAULT”.

Calibration Fault

If during calibration the sensor circuitry is unable to attain the proper adjustment for zero or span, the sensor
will enter into the calibration fault mode and cause the display to alternate between the sensor’s current status

reading and the calibration fault screen which appears as: “CAL FAULT”.

Fail-Safe/Fault Supervision

S gas sensors incorporate a comprehensive program to accommodate easy operator

2

Detcon MicroSafe™ sensors are programmed for fail-safe operation. Either fault condition will activate the

fault relay, illuminate the fault LED, and cause the display to read its corresponding fault condition: “SIGNAL

FAULT”, or “CAL FAULT”. A “SIGNAL FAULT” will also cause the mA output to drop to zero (0) mA.
Sensor Life

The sensor life feature is a reference based on signal output from the sensor cell. When a sensor life of 25% or
less remains the sensor cell should be replaced within a reasonable maintenance schedule.

9. RS-485 Protocol

Detcon MicroSafe™ sensors feature Modbus™ compatible communications protocol and are addressable via
rotary dip switches for multi-point communications. Other protocols are available. Contact the Detcon factory
for specific protocol requirements. Communication is two wire, half duplex 485, 9600 baud, 8 data bits, 1 stop
bit, no parity, with the sensor set up as a slave device. A master controller up to 4000 feet away can
theoretically poll up to 256 different sensors. This number may not be realistic in harsh environments where
noise and/or wiring conditions would make it impractical to place so many devices on the same pair of wires.
If a multi-point system is being utilized, each sensor should be set for a different address. Typical address
settings are: 01, 02, 03, 04, 05, 06, 07, 08, 09, 0A, 0B, 0C, 0D, 0E, 0F, 10, 11, etc.

In most instances, RS-485 ID numbers are factory set or set during installation before commissioning. If
required, the RS-485 ID number can be set via rotary dip switches located on the preamp circuit board.
However, any change to the RS-485 ID number would require the sensor housing to be opened, thus
declassification of the area would be required. See section 3.5.4-f for details on changing the RS-485 ID
number.

The following section explains the details of the Modbus™ protocol that the Detcon MicroSafe™ sensor
supports.

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 18 of 28

Mdl 1000 H2S E-Chem / Inst. Air

Code 03 - Read Holding Registers is the only code supported by the transmitter. Each transmitter contains 6

holding registers which reflect its current status.
Register # High Byte Low Byte
40000 Gas type Sensor Life
Gas type is one of the following:

01=CO, 02= H

S, 03=SO2, 04=H2, 05=HCN, 06=CL2, 07=NO2, 08=NO, 09=HCL, 10=NH3, 11=LEL, 12=O2

2

Sensor life is an estimated remaining use of the sensor head, between 0% and 100%
Example: 85=85% sensor life

Register # High Byte Low Byte
40001 Detectable Range

i.e. 100 for 0-100 ppm, 50 for 0-50% LEL, etc

Register # High Byte Low Byte
40002 Current Gas Reading

The current gas reading is stored as a whole number. If the reading is displayed as 23.5 on the display, this
register would contain the number 235.

Register # High Byte Low Byte
40003 Alarm 1 Set point

This is the trip point for the first alarm.

Register # High Byte Low Byte
40004 Alarm 2 Set point

This is the trip point for the second alarm.

Register # High Byte Low Byte
40005 Status Bits Status Bits

High Byte
Bit 7 Not used, always 0
Bit 6 Not used, always 0
Bit 5 Not used, always 0
Bit 4 Not used, always 0
Bit 3 1-Unit is in calibration 0-Normal operation
Bit 2 1-Alarm 2 is ascending 0-Alarm 2 is descending
Bit 1 1-Alarm 2 is normally energized 0-Alarm 2 is normally de-energized
Bit 0 1-Alarm 2 is latching 0-Alarm 2 is non-latching

Low Byte
Bit 7 1-Alarm 2 Relay is energized 0-Alarm 2 Relay is not energized
Bit 6 1-Alarm 1 is ascending 0-Alarm 1 is descending
Bit 5 1-Alarm 1 is normally energized 0-Alarm 1 is normally de-energized
Bit 4 1-Alarm 1 is latching 0-Alarm 1 is non-latching
Bit 3 1-Alarm 1 Relay is energized 0-Alarm 1 Relay is not energized
Bit 2 1-Fault is normally energized 0-Fault is normally de-energized

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 19 of 28

Mdl 1000 H2S E-Chem / Inst. Air

Bit 1 1-Fault is latching 0-Fault is non-latching
Bit 0 1-Fault Relay is energized 0-Fault Relay is not energized

The following is a typical Master Query for device # 8:
Field Name HEX DEC RTU
Slave Address 08 8 0000 1000
Function 03 3 0000 0011
Start Address Hi 00 0 0000 0000
Start Address Lo 00 0 0000 0000
No. of Registers Hi 00 0 0000 0000
No. of Registers Lo 06 6 0000 0110
CRC ## #### ####
CRC ## #### ####

The following is a typical Slave Response from device # 8:
Field Name HEX DEC RTU
Slave Address 08 8 0000 1000
Function 03 3 0000 0011
Byte Count 0C 12 0000 1100
Reg40000 Data Hi 02 2 0000 0010
Reg40000 Data Lo 64 100 0110 0100
Reg40001 Data Hi 00 0 0000 0000
Reg40001 Data Lo 64 100 0110 0100
Reg40002 Data Hi 00 0 0000 0000
Reg40002 Data Lo 07 7 0000 0111
Reg40003 Data Hi 00 0 0000 0000
Reg40003 Data Lo 0A 10 0000 1010
Reg40004 Data Hi 00 0 0000 0000
Reg40004 Data Lo 14 20 0001 0100
Reg40005 Data Hi 05 5 0000 0101
Reg40005 Data Lo 50 80 0101 0000
CRC ## #### ####
CRC ## #### ####

Additional Notes:

The calibration LED will light when the transmitter is sending a response to a Master Query. Communications
are 9600 baud, 8 data bits, 1 stop bit, No parity, and half duplex 485.

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 20 of 28

Mdl 1000 H2S E-Chem / Inst. Air

10. Display Contrast Adjustment

Detcon MicroSafe™ sensors feature a 16 character backlit liquid crystal display. Like most LCDs, character
contrast can be affected by viewing angle and temperature. Temperature compensation circuitry included in
the MicroSafe™ design will compensate for this characteristic; however temperature extremes may still cause
a shift in the contrast. Display contrast can be adjusted by the user if necessary. However, changing the
contrast requires that the sensor housing be opened, thus declassification of the area is required.

To adjust the display contrast, remove the enclosure cover and use a jeweler’s screwdriver to turn the contrast

adjust screw located beneath the metallic face plate. The adjustment location is marked “CONTRAST”.

11. Low Flow Fault Options

Model 1000 Analyzers offer two low flow fault option PCB’s. One monitors for low sample gas flow, and the
second monitors for low airflow dilution. The Low Flow Fault option for sample gas flow is usually set for
the relay contacts to fire at flow rates ≤ 100cc/min. The Flow Fault option for air dilution is usually set for the
relay contacts to fire at flow rates ≤ 300cc/min. These set points are factory set. Should it become necessary
to adjust the flow fault set points in the field, adjust the flow to the set point target (100 or 300cc/min.) at
Rotameter(s) and adjust the potentiometer on the corresponding Low Flow Fault PCB until the fault LED
toggles between “ON” and “OFF”.

12. Sensor Replacement

Should the electrochemical H
following procedure:
1 - (A) If the sensor is mounted in a classified area, system power to the transmitter must first be removed
before proceeding further.
(B) If in an unclassified area, remove front enclosure cover and unplug transmitter module.
2 - Remove gas flow adapter and tubing connections to expose sensor housing.
3 - Unscrew the three screws of the sensor head bottom.
4 - Pull the sensor head bottom down and off.
5 - Grasp the electrochemical sensor cell and unplug by pulling down.
6 - Plug in the new sensor. Replace the sensor head bottom and screw in place.
7 - Re-attach gas inlet adapter and tubing connections.
8 - Restore system power (if classified) or plug in transmitter module and replace enclosure cover (if
unclassified).
9 - Perform a new zero and span calibration after 1-2 hours of warm-up time.

S plug-in sensor (part number 370-323200-000) require replacement, use the

2

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 21 of 28

Mdl 1000 H2S E-Chem / Inst. Air

13. Troubleshooting

Reading higher or lower than anticipated
Probable cause: Incorrect sample flow or air flow, degraded cal gas, or needs to be zero and span calibrated.

1. Check for correct sample flow “S→ ” marking 200cc/min.

2. Check for correct air flow “→” marking 500cc/min.

3. Check span gas is same as programmed AutoSpan value.

4. Check Span Calibration gas for valid concentration in nitrogen gas using H

5. Re-calibrate sensors with known good span gas.

6. Re-zero sensor per instruction manual.

“Span Fault” Error

1. Check for correct calibration gas flow “C→” marking, 250cc/min.

2. Check for correct air flow “→” marking, 500cc/min.

3. Check Span Calibration gas for valid concentration in nitrogen gas using H

4. Re-calibrate with known good span gas.

5. Consider electrochemical sensor replacement if reported Sensor Life is <50%.

Slow sensor response during Span Calibration
Probable cause: Incorrect sample flow or airflow, or bad span gas, or slow response sensor.

1. Check for correct calibration gas flow “C→” marking, 250cc/min.

2. Check for correct air flow “→” marking, 500cc/min.

3. Check Span Calibration gas for valid concentration in nitrogen gas.

4. Re-calibrate with known good span gas.

5. If problem persists, the sensor may need to be replaced. Contact factory.

Sample gas and/or air flow reduced, Flow Fault lights activated (optional)
Probable cause: Incorrect sample gas inlet pressure or the sample gas or airflow has been obstructed by,
blocked Genie membrane filter, failed air pump, vent lines blocked, rotameters accidentally turned down.

1. Check for liquid in the sample flow inlet line.

2. Check for adequate sample gas inlet pressure (10 ±2psig).

3. Check for obstruction in the air-inlet pump.

4. Open the Sample by-pass liquid rejection port to release any liquid trapped in the Genie Membrane filter.
Leave sample by-pass open to allow ~100-200cc/min of gas out.

5. Replace Genie membrane if permanently blocked.

S pull tube.

2

S pull tube.

2

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 22 of 28

Mdl 1000 H2S E-Chem / Inst. Air

14. Spare Parts

Part# Description

327-000000-000 Programming Magnet
360-2424GH-030 24V DC-DC Converter
360-205421-024 24 VDC Power Supply Assembly
943-010013-505 500 CC Fixed Flow Regulator
823-101085-882 Genie Membrane Filter
350-300000-000 0.5Lpm Rotameter no valve
348-900000-000 1Lpm Rotameter with valve
350-523081-02K Mass flow controller
308-091000-030 Pressure Gauge 0-30 PSIG
985-240600-384 In-Line Humidifying Tube

+

+

24VDC

18-36

OUT

VDC

2.1A

IN

24V DC-DC

Converter

24VDC Power Supply

(Mounted under Connector PCA)

PART NO.

MODEL NO.
SERIAL NO.
INPUT VOLTAGE
FREQUENCY
CURRENT LOAD
AREA CLASSIFICATION

3200 A-1 Research Forest Dr.
The Woodlands, TX 77381

www.detcon.com

detcon inc.

Inline Humidity Tube

1.0Lpm Air
Rotameter

Mass Flow Control

0.5Lpm Sample

AIR

INLET

AIR

FLOW

SAMPLE PRESSURE
10 PSIG (CONSTANT)

SAMPLE

FLOW

Rotameter

0-30psi

Pressure Guage

SAMPLE

INLET

Genie Membrane

Filter

DM-624

Transmitter

Module

H2S Sensor Head and

Plug-in Replacement Sensor

Figure 14 Analyzer Parts Identification

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 23 of 28

Mdl 1000 H2S E-Chem / Inst. Air

Spare Parts DM-624 H2S Sensor
Part# Description

942-010212-XXX Calibration Span Gas (XXXppm H

S, balance nitrogen)

2

(Where XXX denotes the gas level – 010 = 10ppm, 025 = 25ppm, 050 = 50ppm)
926-245502-XXX Transmitter Module XXXppm Range (for H

S Alcohol Free gas sensor)

2

(Where XXX denotes the Range – i.e.: 005 = 0-5ppm, 010 = 0-10ppm, 020 = 0-20ppm, etc.)
404-0H2S3H-NXX Sensor Housing Assembly
(Where XX denotes Range – i.e.: N5K = 0-5000ppm, N1P = 0-2%, N2P = 0-2%, etc.)
017-501500-574 O-Ring 1.5”ID X 1.6”OD X 0.05”W
017-26530H-000 O-Ring 1 3/16”ID X 1 3/8”OD X 0.103”W
370-3H3H00-000 High Range H2S Cell (Used for ranges ≥1000ppm)

Condulet Cover with

Plug in Transmitter Module

Connector Board

O-Rings

Sensor Housing Assembly

Replacement

Cell

Window

Condulet

Base

Figure 15 DM-624 Replacement Parts

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 24 of 28

Mdl 1000 H2S E-Chem / Inst. Air

15. Warranty

Detcon Inc., as manufacturer, warrants under intended normal use each new Model 1000 Series H
Analyzer gas detection system to be free from defects in material and workmanship for a period of one year
from the date of shipment to the original purchaser. All warranties and service policies are FOB the Detcon
Inc. facility located in The Woodlands, Texas.

Sensor Transmitter

Detcon, Inc., as manufacturer, warrants under intended normal use each new MicroSafe™ plug-in control
circuit to be free from defects in material and workmanship for a period of two years from the date of shipment
to the original purchaser.

Detcon, Inc., further provides for a five year fixed fee service policy wherein any failed transmitter shall be
repaired or replaced as is deemed necessary by Detcon, Inc., for a fixed fee of $65.00. The fixed fee service
policy shall affect any factory repair for the period following the two-year warranty and shall end five years
after expiration of the warranty. All warranties and service policies are FOB the Detcon facility located in The
Woodlands, Texas.

DM-624 Electrochemical H

S Sensor Element Warranty

2

S Process

2

Detcon, Inc., as manufacturer, warrants each hydrogen sulfide sensor cell (part no. 370-323200-000), for a 6­month period under the conditions described as follows: The warranty period begins on the date of shipment to
the original purchaser and ends six months thereafter. The sensor cell is warranted free from defects in
material and workmanship. Should any sensor cell fail to perform in accordance with published specifications
within the warranty period, return the defective part to Detcon, Inc.

 The original serial number must be legible on each sensor element base.
 Shipping point is FOB the Detcon Factory.
 Net payment is due within 30 days of invoice.
 Detcon, Inc. reserves the right to refund the original purchase price in lieu of sensor replacement.

Terms & Conditions

 The original serial number must be legible on each sensor element base.
 Shipping point is FOB the Detcon factory.
 Net payment is due within 30 days of invoice.
 Detcon, Inc. reserves the right to refund the original purchase price in lieu of sensor replacement.

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 25 of 28

Mdl 1000 H2S E-Chem / Inst. Air

16. Flow Diagrams

PART NO.
MODEL NO.
SERIAL NO.
INPUT VOLTAGE
FREQUENCY
CURRENT LOAD
AREA CLASSIFICATION

3200 A-1 Research Forest Dr.

The Woodlands, TX 77381

www.detcon.com

detcon inc.

AIR

AIR

INLET

AIR

FLOW

Sample

SAMPLE

INLET

SAMPLE PRESSURE
10 PSIG (CONSTANT)

SAMPLE

FLOW

Input

SAMPLE CALIBRATE

VentVentVent

Figure 16 Unit Flow Diagram

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 26 of 28

Mdl 1000 H2S E-Chem / Inst. Air

17. Wiring Diagram

Red 18AWG

Black 18AWG

30

31

1 2 3 4 5 6 7 8 9 1011121314151617181920212223242526272829

Blue 18AWG

Gray 18AWG

Violet 18AWG

Orange 18AWG

White 18AWG

+

24VDC

OUT

2.1A

Tan 18AWG

Brown 18AWG

Blue 18AWG

Black 18AWG

Green 18AWG

Yellow 18AWG

+

18-36

VDC

IN

Tan 18AWG

Gray 18AWG

White 18AWG

Brown 18AWG

Yellow 18AWG

40

41

Red 18AWG

Gray 18AWG

Gray 18AWG

Black 18AWG

Green 18AWG

Brown 18AWG

Brown 18AWG

Orange 18AWG

Orange 18AWG

Connector Board

32 33 34 35 36 37 38 39

40 41

Red 18AWG

Red 18AWG

Black 18AWG

Red 18AWG

Black 18AWG

Red 18AWG

Black 18AWG

Red 18AWG

Black 18AWG

Black 18AWG

24VDC +

24VDC Com
120VAC (L1)

Neutral (N)
Ground

DC IN

(Optional)

AC IN

Customer Supplied

Power Supply
Box Assembly

White 18AWG
Black 18AWG
Green 18AWG

Black 18AWG

Gnd

P1

NFS40-7624

24VDC Power

321

L1 N

Supply

+

+

25

26

Green 16AWG

J1

123456

J1

Green 16AWG

Pump Box

Assembly

192021

123

Sample

Flow Fault

(Optional)

11

12

13

14

15

16

COM

COM

Fault

mA
A
B
A
B

VDC Power In
4-20mA Output
RS-485 In

RS-485 Out

Assembly

Alarm Dry Contacts

Sensor

38
39

18

17

1
2

COM

30

31

Red

Black

Pump

Assembly

34
35

Air Flow

Fault (optional)

24

33
32

123

22

23

Figure 17 Wiring Diagram

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 27 of 28

Mdl 1000 H2S E-Chem / Inst. Air

Appendix C

Revision Log

Revision Date Changes made Approvals

0.0 10/31/09 Manual Created BM

1.0 06/13/11 Updated drawings and Spare parts list. Added approvals
column to revision log

1.1 09/19/11 Update to notation in section 3.3 regarding VDC input to
match wiring diagram

LU

LU

Shipping Address: 3200 A-1 Research Forest Dr., The Woodlands Texas 77381

Mailing Address: P.O. Box 8067, The Woodlands Texas 77387-8067

Phone: [phone] • Fax: [phone] •

Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 28 of 28

www.detcon.com • [e-mail]