Evikon PluraSens E2638 Series User manual

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PluraSens®
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Hydrogen Sulfide Detector-Transmitter
E2638-H2S
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User Manual
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E2638-H2S Rev 10.03.2021
Table of contents
Hydrogen Sulfide 3
Specifications 4
Product description 6
Safety requirements 6
Operating conditions 7
Installation guidelines 7
Mounting dimensions 8
Sensor probe handling 9
Gas sensor replacement procedures 9
Electrical connections 10
Operation 12
Maintenance 12
Calibration 12
Delivery set 13
Order code for E2638-H2S options 13
Configuring 14
Return to default settings 14
Modbus RTU Communication 15
RS485 communication interface 15
Communication parameters 15
Modbus holding registers 15
Warranty 20
Manufacturer contacts 20
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2

E2638-H2S Rev 10.03.2021
Hydrogen Sulfide
Colorless toxic, corrosive and flammable gas with a smell of rotten eggs. Occurs in natural              
gas, volcanic gases, petroleum, and some sources of well water. It results from the             
anaerobic decay of sulfur-containing proteins, e.g. in sewers.
Synonyms: Hydrosulfuric acid, Sewer gas, Sulfuretted hydrogen.
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Conversion of ppm to mg/m3 is calculated for 25°C and 1 atm.
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3
Chemical formula
H2S
Molar weight
34
Conversion
1 ppm = 1.40 mg/m3
Relative gas density (to air)
1.17
Boiling point
−60 °C
Low explosive limit (LEL), % vol. in air
4.0
Upper explosive limit (UEL), % vol. in air
44.0
Odor
The characteristic smell of rotten eggs. Above 30 ppm,
the odor is described as sweet or sickeningly sweet.
Odor threshold
0.01-1.5 ppm
Note: Sense of smell becomes rapidly fatigued and can
NOT be relied upon to warn of the continuous presence of
H2S.
Hazards
Highly flammable, explosive gas.
Broad-spectrum poison, mostly affecting the nervous
system. At low concentrations causes eye irritation, a
sore throat and cough, nausea, shortness of breath, and
pulmonary edema. Long-term, low-level exposure results
in fatigue, loss of appetite, headache, poor memory,
irritability, and dizziness. Exposure to high levels can
induce immediate collapse, with loss of breathing and a
high probability of death.
Exposure limits 
(Commission
Directive
2009/161/EU)
TWA
7 mg/mm3 / 5 ppm
STEL
14 mg/mm3 / 10 ppm
IDLH (NIOSH)
140 mg/mm3 / 100 ppm

E2638-H2S Rev 10.03.2021
Specifications
4
Sensor type
Electrochemical cell
Sampling method
Diffusion
Typical detection range
0...100 ppm
0...2000 ppm
Maximum overload
500 ppm
4000 ppm
Resolution / digital unit
0.1 ppm
1 ppm
Response time T90
< 30 s
< 25 s
Operating temperature
-30...+50 °C
-40...+50 °C
Sensor lifetime
> 2 years
Calibration interval
6 months
Signal update
Every 1 second
Power supply
11...30 VDC,
24 VAC or 90...265 VAC as options
Power consumption
< 2 VA
Analog outputs
2 × 4-20 mA / 0-10 V, user settable
Load resistance
RL < (Us - 2 V) / 22 mA for 4-20 mA
RL > 250 kOhm for 0-10 V mode
Digital interface
RS485, Modbus RTU protocol; No galvanic isolation
Enclosure
Grey ABS, wall mount, protection class IP65
Dimensions
H90 × W145 × D55 mm
(overall dimensions H140 × W145 × D55 mm)
Outputs assignment
OUT1 gas; OUT2 gas
NOTE! for the LCD version only output 1 is available
Output scale width
> 10 × resolution
Recommended: 20-100% of the detection range
CE marking
According to 2014/30/EU and 2014/35/EU, EN 50491-4-1:2012
EN 61000-6-3:2020, EN 61326-1:2013(EMC, emissions)
EN 61000-6-1:2019, EN 61000-6-2:2019(EMC, Immunity)
EN 60079-29-1:2016, EN 60079-29-2:2015 and EN 60079-29-3:2014
Operating conditions
(operating temperature is specified above)
15...90% RH Non-condensing, 0,9...1,1 atm
Explosion-safe areas,
Non-aggressive atmosphere

E2638-H2S Rev 10.03.2021
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5
Relay option
Output relays
2 × SPST relays (closing contact),
250 VAC / 30 VDC, 5 A max
Default alarm setpoints
(set/release)
LOW: 10 ppm/ 8 ppm
HIGH: 20ppm/16 ppm
Determined by user
within 5-95% of the range
Signaling options
Visual
Red and green LEDs
Acoustic alarm
Buzzer 85 dB
LCD indicator option
Operating temperature
0...+50 °C
Display dimensions
72 × 36 mm
Number of digits
3.5 7-segment
Character height
14 mm
Other features
backlight
Other options
Remote probe
Protection IP65, default cable length 3.0 m;
max height 80 mm, max diameter 65 mm

E2638-H2S Rev 10.03.2021
Product description
E2638 series detectors-transmitters belong to the PluraSens® family of multifunctional         
measurement instruments. The instruments utilize gas sensors of various types with          
excellent repeatability, stability, and long lifetime.
E2638 series provides two independent analog outputs OUT1 and OUT2, user-selectable to           
4-20 mA or 0-10 V, proportional to gas concentrations. RS485 Modbus RTU digital            
communication interface allows easy instrument configuration and integration into various         
automation systems.
The following features are available as an option:
●Two relays RE1 and RE2 with closing contacts. Relay outputs can be used to             
switch alarm sirens, ventilation fans, shut-off valves, or other actuators,
●Acoustic (85 dB buzzer) and visual (red and green LED) signaling,
●24 VAC or 230 VAC as options for power supply module,
●LCD indicator,
●Remote probe.
The version of your device is marked on the package. If the symbol ⚠ is marked on the                 
equipment, consult the documentation for further information.
Safety requirements
Misuse will impair the protection of the product. Always adhere to the safety provisions             
applicable in the country of use.
Do not perform any maintenance operation with the power on. Do not let water or foreign               
objects inside the device.
Removal of the PCB from the enclosure voids the warranty. Do not touch the electronic              
components directly, as they are sensitive to static electricity.
Connection diagrams can be found in the electrical connections section. The device might            
not perform correctly or be damaged if the wrong power supply is connected.
External circuits connected to the equipment should have sufficient insulation rating          
according to the environmental conditions and equipment power.
A disconnecting device that is marked as such and easily accessible should be included in              
the installation of this product.
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E2638-H2S Rev 10.03.2021
Operating conditions
The device should be used both in a non-hazardous area and in a basic electromagnetic              
environment, where the latter is defined in EN 61326-1. Avoid strong mechanical shock and             
vibrations. Avoid corrosive atmosphere and areas highly contaminated with dust, oil mist,           
etc. Keep the instrument away from direct sunlight. A sudden temperature or humidity            
change might affect the sensitivity of the sensor.
Installation guidelines
Before proceeding with the installation it is mandatory to read the Safety requirements            
section and make sure to comply with all listed instructions. Installation standards EN            
60079-29-2 and EN 45544-4 are also recommended for further instructions and related           
information about the installation. During the installation of the detector-transmitter the          
following points must be considered:
●Application (air quality control or leakage detection)
●Properties of the space under investigation (room geometry, direction, and         
velocity of airflows, etc.),
●Hydrogen sulfide is slightly heavier than air and spreads evenly in the room. The             
recommended location is close to the potential leakage source.
●The device should be accessible for maintenance and repair.
The aforementioned conditions above will affect the coverage area of the device. however,            
the coverage area for a transmitter is usually between 2.5 to 5 meters radius.
For early leakage detection install the sensor as close as possible to the potential leakage              
sources (flanges, valves, pressure reducers, pumps, etc.), taking into consideration other          
points listed above.
For general area monitoring without definite leakage sources, the detectors should be           
distributed evenly in the room.
For personal safety control, the detectors are installed in the breathing zone (at the height              
of the head of people or animals). The recommended sensor position is vertical, pointing             
downwards.
For installing the device, attach the device to the wall using provided screws through the              
side mounting holes or key slots (see mountains dimensions).
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E2638-H2S Rev 10.03.2021
Mounting dimensions
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Front view
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Bottom view
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E2638-H2S Rev 10.03.2021
Sensor probe handling
The E2638 series devices are available with a remote probe. The remote probe is             
connected to the main unit with a shielded cable. The default remote probe cable length is               
3 m.
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A) Wall mount remote probe with fixing clamp (default version),
B) Remote probe with rubber flange and three self-tapping screws (on request)
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The sensor probes of all types are equipped with a hydrophobic microporous PTFE filter to              
protect the sensor from dust, dirt, and water drops. The filter should be replaced if it gets                
strongly contaminated. To replace the PTFE filter, unscrew the sensor head cap and            
remove the old filter. Place a new filter into the cap and tighten it again.
NOTE! Never stab or press the filter near its center where the sensor is located since this                
may damage the sensor. Do not remove the filter as it may cause the device to show                
incorrect values and/or break the sensor.
The recommended orientation of the sensor probe is vertical with the sensor tip pointing             
downwards. This prevents the possible accumulation of condensed water on the sensor           
protection filter.
Gas sensor replacement procedures
1. Remove the sensor head cap from the device (or the remote probe),
2. Remove the PTFE filter (if it is not removed within the cap),
3. Remove the O-ring rubber,
4. Detach the electrochemical sensor from the device,
5. Insert the new electrochemical sensor inside,
6. Put back the O-ring rubber, PTFE filter, and the head cap, respectively.
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E2638-H2S Rev 10.03.2021
Electrical connections
Unscrew four lid screws and detach the lid from the device. Use two M16 cable glands to                
let in the cables of the power supply and of the external devices. Without turning on the                
power, plug the power cable, and connect the analog/relay outputs and/or digital interface            
terminals to the necessary devices according to the relevant connection diagram.
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Version with PSU and relays Version with PSU and without relays
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Version without PSU and with relays Version without PSU and relays
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E2638-H2S Rev 10.03.2021
The screwless quick connect spring terminals on the E2638 series devices are suitable for             
a wide range of wires with a cross-section of 0.2...1.5 mm2. We recommend to strip the               
wire end by 8...9 mm and use wire end sleeves.
To connect the wire, insert the wire end into the terminal hole. To disconnect, push the               
spring-loaded terminal lever, pull the wire out, and release the lever.
Use a twisted-pair cable, e.g. LiYY TP 2×2×0.5 mm2or CAT 5, to connect the device to the                 
RS485 network. A and B on the device represent DATA+ and DATA- respectively, polarity             
must be respected when connecting to an external RS485 network. 
Both analog outputs can be independently changed between 4-20 mA and 0-10 V type             
using jumpers J1 (OUT1) and J2 (OUT2). By closing pins on a specific jumper the related               
output is 0-10 V, with an open jumper the output is 4-20 mA. Power restart is required after                 
changing the position of the jumpers.
NOTE! The outputs are not galvanically isolated from the external power supply and share             
common 0V. Allowed load resistance limits are stated in the Specifications table. To power             
the instrument from an external power source, connect terminals 0V and +U to the source.              
If the integrated mains power supply module is used, connect terminals L and N to the               
mains.
NOTE! Actuator short-circuits should be avoided, to protect the instrument relays, use           
external fuses or safety switches.
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E2638-H2S Rev 10.03.2021
Operation
Turn on the power. The instrument warm-up time takes about 1 minute after switching on              
and the final sensor stabilization time to maximum accuracy takes about 30 minutes. The             
operating status is indicated by the LED on the PCB of the device. The control LED (red)                
response to different processes is presented in the following table:

Make sure that the detector-transmitter is properly mounted, the external devices          
connected, power LED (green) on and control LED (red) constantly lit. Place the lid back              
and fix it with the screws. The device is ready to use.
Maintenance
Do not perform any maintenance operation with the power on.
Clean the device with a soft damp cloth. Do not use any abrasive cleaning agents. Do not                
immerse the device in water or any cleaning media.
Calibration
E2638-H2S gas detector-transmitters have been calibrated by the Manufacturer with         
standard gas mixtures before delivery. Provided that the sensor is used under moderate            
conditions, the recommended interval for field recalibration is 6 months. Please contact           
your dealer for more information.

12
Mode
LED mode
During calibration mode or sensor heating
period (if activated)
0.5 Hz (50% on, 50% off)
Relay 1 turned on
Blinking 1 Hz (50% on, 50% off)
Relay 2 turned on
Blinking 2 Hz (50% on, 50% off)
During Modbus communication cycle
Short on-off pulses
Normal operating/measurement
Continuously on or off

E2638-H2S Rev 10.03.2021
Delivery set
●Detector-transmitter E2638
●Mounting accessories:
○4 screws with plastic dowels
○Fixing clamp for remote probe version


Order code for E2638-H2S options

13
E2638 options
Order code
Remote probe, 3 m cable
E2638-H2S-RP33-3
Remote probe, 10 m cable
E2638-H2S-RP33-10
Duct mount option, stem Ø35×L230 mm
E2638-H2S-DM
Integrated 24 VAC power supply module 
E2638-H2S-24VAC
Integrated 90...265 V mains power supply module
E2638-H2S-230
Local LCD single value display 36 mm x 72 mm
E2638-H2S-LCD
Remote LCD single value display, wall mount box
115 × 65 × 40mm, 3 m cable
E2638-H2S-RLCD3
Two SPST relays
E2638-H2S-R
Two LEDs (visual alarm)
E2638-H2S-LED
Buzzer (acoustic alarm)
E2638-H2S-B
Self-test button for relays
E2638-H2S-TB
Integrated coreless micropump
E2638-H2S-MP

E2638-H2S Rev 10.03.2021
Configuring
A standard configuration kit includes a USB-RS485 converter, fixed flow regulator, gas           
tubing with applicators, and a software pack. Please contact your Seller for more            
information.
Detectors-transmitters E2638 share all functionalities of the PluraSens® multifunctional        
platform. The features and options include:
●Digital output change rate-limiting filter
●Digital integrating (averaging) filter
●Free assignment of each analog output to the chosen parameter
●Flexible setting of analog output scales for each output
●Output zero and slope adjustment for calibration
●Free assignment of each of two relays to the chosen parameter
●Several relay control logic modes
●Switch delays and minimum on/off state durations for each relay

The output scales can be changed by Modbus commands by using the configuration            
software and the standard configuration kit (see Modbus RTU Communication).
Return to default settings
To reset the device’s Slave ID, baud rate, and stop bit numbers to factory settings, proceed               
as follows:
1. De-energize the device 
2. Connect the X6 jumper
3. Turn on the device 
4. De-energize the device
5. Disconnect the X6 jumper 
6. Turn on the device
 
14

E2638-H2S Rev 10.03.2021
Modbus RTU Communication
RS485 communication interface


Communication parameters

Modbus holding registers
Register addresses are shown 0-based, Address in hexadecimal, Reg in decimal format.           
Modbus holding register numbers MHR are shown in the decimal 1-based format and may             
be addressed either from 00001 or 40001 base.

15
Databits: 8 
Parity: none / odd / even 
Stop bits: 1 or 2 
Protocol: Modbus RTU
Supported Modbus functions:
03 – Read multiple registers
06 – Write a single register
Parameter
Permitted values
Default
Supported baud rates
1200, 2400, 4800, 9600, 19200, 38400, 57600
9600
Data bits
8
8
Parity
none / odd / even
none
Stop bits
1, 2
1
Protocol
Modbus RTU

Modbus functions
03 - Read multiple registers
06 - Write a single register
Error codes
01 – Illegal function
02 – Illegal data address
03 – Illegal data value
04 – Slave device failure
(details of last error 04 can be read from register 0x0008)
Address
Reg / MHR
RW
Description
Supported values (dec)
Default
0x0001
1 / 40002
R
Hardware version

-
0x0002
2 / 40003
R
Software version

-
0x0003
3 / 40004
R
Product serial number
1...65535
-
0x0004
4 / 40005
RW
Slave ID (net address) *
1...247 **
1

E2638-H2S Rev 10.03.2021


16
0x0005
5 / 40006
RW
Baud rate *
1200, 2400, 4800, 9600, 19200,
38400, 57600
9600
0x0006
6 / 40007
RW
Response delay, ms
1...255
10
0x0007
7 / 40008
RW
Stop bits, parity bit *
1 – No parity bit, 1 stop bit
(default after factory reset)
2 – No parity bit, 2 stop bits
3 – Odd parity, 1 stop bit
4 – Even parity, 1 stop bit
NOTE: 3 and 4 are available
starting from the Software
version 0x218 (dec. 536)
1
0x0008
8 /40009
R
Last error code
1...255
-
0x0011
17 / 40018
RW
Technological:
age of last data in seconds
(read) / restart (write)
0...65535 s (read),
writing 42330 restarts the
instrument
-
0x00A5
165 /
40166
RW
Zero adjustments for gas
data, ADC
-32000...+32000 ADC units
0
0x00A6
166 /
40167
RW
Slope adjustment for gas
data
1...65535
512
0x00A7
167 /
40168
RW
Change rate limit for gas
units/ s
1...32000, 0 - no limit
0
0x00A8
168 /
40169
RW
Integrating filter time
constant, s
1...32000 (seconds),
0 - no filter
0
Address
Reg / MHR
RW
Description
Supported values (dec)
Default
0x00C9
201 /
40202
RW
Parameter tied to analog
output 1
0 – None
2 – Gas concentration
9 – Forced Modbus control, 
value set in MHR / 40204
2
0x00CA
202 /
40203
RW
Parameter tied to analog
output 2
0 – None
2 – Gas concentration
9 – Forced Modbus control,
value set in MHR / 40205
2
0x00CB
203 /
40204
RW
Forced value for analog
output 1***
0...1000
(0.0%...100.0% of output
scale)
0
0x00CC
204 /
40205
RW
Forced value for analog
output 2***
0...1000
(0.0%...100.0% of output
scale)
0

E2638-H2S Rev 10.03.2021


17
0x00D3
211 /
40212
RW
Parameter tied to relay
RE1
0 –none
2 – gas concentration
9 – control by Modbus
control, state set in MHR /
40214
2
0x00D4
212 /
40213
RW
Parameter tied to relay
RE2
0 – none
2 – gas concentration
9- – control by Modbus
control, state set in MHR /
40215
2
0x00D5
213 /
40214
RW
Forced state for relay
RE1***
0 –off, 1 – on
0
0x00D6
214/ 40215
RW
Forced state for relay
RE2***
0 – off, 1 – on
0
0x00D7
215 /
40216
RW
Switching delay for relay
RE1
0...1000 (s)
0
0x00D8
216 /
40217
RW
Switching delay for relay
RE2
0...1000 (s)
0
0x00D9
217 /
40218
RW
Minimal on/off time for
relay RE1
0...1000 (s)
0
0x00DA
218 /
40219
RW
Minimal on/off time for
relay RE2
0...1000 (s)
0
Address
Reg / MHR
RW
Description
Supported values (dec)
Default
0x00DB
219 /
40220
RW
Control logic for relay RE1
0 – none
1 – relay on at high values
2 – relay on at low values
3 – relay on at values within
the range
4 – relay on for the values out
of the range
0

E2638-H2S Rev 10.03.2021
18
0x00DC
220 /
40221
RW
Control logic for relay RE2
0 – none
1 – relay on at high values
2 – relay on at low values
3 – relay on at values within
the range
4 – relay on for the values out
of the range
0
0x00DD
221 /
40222
RW
LOW setpoint for relay
RE1
0...65535 (gas units)
see
Specifications
0x00DE
222 /
40223
RW
HIGH setpoint for relay
RE1
0...65535 (gas units)
see
Specifications
0x00DF
223 /
40224
RW
LOW setpoint for relay
RE2
0...65535 (gas units)
see
Specifications
0x00E0
224 /
40225
RW
HIGH setpoint for relay
RE2
0...65535 (gas units)
see
Specifications
0x00FF
255 /
40256
RW
Sensor, analog outputs,
LED and buzzer status
bit[0]=0/1 – sensor
present/absent, RO
bit[1]=0/1 – analog outputs
deactivated/activated
bit[2]=0/1 – in case the
sensor is absent, turn
signaling off/on analog
output1
bit[3]=0/1 – in case the
sensor is absent, turn on
signaling with low
current/high current on
analog output1; if bit[2]=0 this
bit will be ignored
bit[4]=0/1 – in case of sensor
absent, turn signaling off/on
analog output2
bit[5]=0/1 – in case of sensor
absent, turn on signaling with
low current/high current on
analog output2; if bit[4]==0
this bit will be ignored
bit[6]=0/1 – current/voltage
output detected on output1,
RO
bit[7]=0/1 – current/voltage
output detected on output2,


E2638-H2S Rev 10.03.2021

* – The new value is applied after restart.
** – Broadcast slave ID 0 can be used to assign a new ID to the instrument with an                  
unknown ID. When addressing by ID 0 the device shall be the only Modbus instrument in               
the network. The device will not respond to the Master command when addressed by ID 0.
*** – This value is dynamic and not kept in EEPROM after a restart.



 
19
RO
bit[8]=0/1 – LED
deactivated/activated
bit[9]=0/1 – buzzer
deactivated/activated
bit[10]=0/1 - LED is on/off in
normal condition
bit[11]=0/1 - 1 Hz (50% on,
50% off) LED signal off/on if
relay1 turned on
bit[12]=0/1 - 2 Hz (50% on,
50% off) LED signal off/on if
relay2 turned on
0x0101
257 /
40258
R
Raw gas sensor data
0...4095, ADC units

0x0103
259 /
40260
R
Gas concentration,
gas units
0...65535, gas units

0x0105
261 /
40262
RW
0% value
for analog output 1
-32000...+32000, gas units
User
defined
0x0106
262 /
40263
RW
100% value
for analog output 1
-32000...+32000 , gas units
User
defined
0x0107
263 /
40264
RW
0% value
for analog output 2
-32000...+32000, gas units
User
defined
0x0108
264 /
40265
RW
100% value
for analog output 2
-32000...+32000, gas units
User
defined

E2638-H2S Rev 10.03.2021
Warranty
This product is warranted to be free from defects in material and workmanship for a period               
of one year from the date of the original sale. During this warranty period, the Manufacturer               
will, at its option, either repair or replace a product that proves to be defective. This               
warranty is void if the product has been operated in conditions outside ranges specified by              
the Manufacturer or damaged by customer error or negligence or if there has been an              
unauthorized modification.



Manufacturer contacts

Evikon MCI OÜ
Teaduspargi 7/9, Tartu
50411 Estonia
[email protected]
www.evikon.eu






20