Evikon PluraSens E2638 Series User manual

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PluraSens®
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Solvent Vapor Detector-Transmitter
E2638-PID
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User Manual
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E2638-PID Rev 10.03.2021
Table of contents
Acetone 4
Benzene 5
Ethanol 6
Ethyl acetate 7
Toluene 8
Xylene 9
Specifications 10
Product description 12
Safety requirements 12
Operating conditions 13
Installation guidelines 13
Mounting dimensions 14
Sensor probe handling 15
Gas sensor replacement procedures 15
Electrical connections 16
Operation 18
PID (photoionization detector) technology 19
Properties of VOC: ionization energy, the correction factor 19
Calibration and maintenance 28
Delivery set 32
Order code for E2638-PID options 32
Configuring 33
Return to default settings 33
Modbus RTU Communication 34
RS485 communication interface 34
2

E2638-PID Rev 10.03.2021
Communication parameters 34
Modbus holding registers 34
Warranty 39
Manufacturer contacts 39
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3

E2638-PID Rev 10.03.2021
Acetone
A colorless organic solvent with a characteristic pungent odor that is volatile and            
flammable with the chemical formula (CH3)2CO.
Synonyms/Trade Names: Dimethyl ketone, Ketone propane, 2-Propanone.
 
4
Chemical formula
(CH3)2CO
Molar weight
58
Relative gas density (to air)
2.0
Conversion*
1 ppm = 2.38 mg/m3
Boiling point
56.11 °C
Low explosive limit (LEL), % vol. in air
2.5
Upper explosive limit (UEL), % vol. in air
12.8
Odor
Characteristic pungent smell
Hazards
Highly flammable.
Slightly toxic in normal use. Irritant causing mild skin
irritation and moderate to severe eye irritation. At high
vapor concentrations, it may depress the CNS.
Exposure limits
8 hours
(2000/39/EC)
1900 mg/m3 / 500 ppm
NIOSH REL TWA
590 mg/m3 /250 ppm
IDLH (NIOSH)
2500 ppm [10%LEL]

E2638-PID Rev 10.03.2021
Benzene
A colorless liquid with an aromatic odor that is highly flammable with the molecular             
formula C6H6.
Synonyms/Trade Names: Benzol, Phenyl hydride.

 
5
Chemical formula
C6H6 
Molar weight
78
Relative gas density (to air)
2.69
Conversion*
1 ppm = 3.19 mg/m3
Boiling point
80 °C
Low explosive limit (LEL), % vol. in air
1.2
Upper explosive limit (UEL), % vol. in air
7.8
Odor
Hyacinth-like odor
Hazards
Highly flammable.
Irritant. Carcinogen.
May cause dizziness; headache, nausea, staggering
gait; anorexia, lassitude.
Target organs: eyes, skin, respiratory system, blood,
central nervous system, bone marrow.
Exposure limits
(NIOSH REL)
Ca TWA
0.319 mg/m3 /0.1 ppm
STEL
15 minutes
1 ppm
Ca IDLH
500 ppm

E2638-PID Rev 10.03.2021
Ethanol
A clear colorless liquid with a faintly sweet odor and pungent taste.
Synonyms/Trade Names: ethyl, alcohol.
 
6
Chemical formula
CH3CH2OH
Molar weight
46
Relative gas density (to air)
1,59
Conversion*
1 ppm = 1.89 mg/m3
Boiling point
78.37°C
Low explosive limit (LEL), % vol. in air
3 - 3.3
Upper explosive limit (UEL), % vol. in air
19
Odor
The characteristic smell of alcohol
Hazards
Highly flammable.
Gas/air mixtures are explosive.
Inhalation of vapors leads to cough, headache, fatigue,
and drowsiness. High concentrations may damage the
fetus. Repeated high exposure may affect the liver and
the nervous system.
Exposure limits 
according to 
Commission
Directive 2006/15/EC
TWA
8 hours
1210 mg/m3 / 1000 ppm
STEL
15 minutes
-

E2638-PID Rev 10.03.2021
Ethyl acetate
A colorless organic compound with a sweet pear-like smell that is highly flammable.
Synonyms/Trade Names: ethyl ester, acetic ester, EA, EtOAc.

 
7
Chemical formula
C4H8O2
Molar weight
88
Conversion*
1 ppm = 3.60 mg/m3
Boiling point
77.1 °C
Low explosive limit (LEL), % vol.     
in air
2
Upper explosive limit (UEL), %    
vol. in air
11.5
Odor
Sweet “pear” smell
Hazards
Flammable.
Short-term exposure to high levels of ethyl acetate results first in
irritation of the eyes, nose, and throat, followed by headache,
nausea, vomiting, sleepiness, and unconsciousness.
Exposure limits 
(NIOSH)
TWA
8 hours
1400 mg/m3 /400 ppm
IDLH
2000 ppm [10%LEL]

E2638-PID Rev 10.03.2021
Toluene
A clear, colorless liquid with a sweet smell that is highly flammable.
Synonyms/Trade Names: methylbenzene, phenylmethane.
 
8
Chemical formula
C6H5CH3 
Molar weight
92
Conversion*
1 ppm = 3.77 mg/m3
Boiling point
110.7°C
Low explosive limit (LEL), % vol.     
in air
1.1 - 1.27
Upper explosive limit (UEL), %    
vol. in air
6.75–7.1
Odor
Characteristic “chemical” smell
Hazards
Highly flammable.
Gas/air mixtures are explosive.
Inhalation possible effects: irritation eyes, nose; lassitude
(weakness, exhaustion), confusion, euphoria, dizziness,
headache; dilated pupils, lacrimation (discharge of tears); anxiety,
muscle fatigue, insomnia; paraesthesia; dermatitis; liver, kidney
damage
Exposure limits 
according to 
Commission
Directive
2006/15/EC
TWA
192 mg/mm3 / 50 ppm
STEL
384 mg/mm3 / 100 ppm

E2638-PID Rev 10.03.2021
Xylene
A colorless, flammable liquid with a chemical smell. Xylenes are produced by the            
methylation of toluene and benzene.
The term is used for any of three isomers of dimethylbenzene, or a combination thereof.
Synonyms/Trade Names: xylol, dimethylbenzene.

Conversion of ppm to mg/m3 is calculated for 25°C and 1 atm.
 
9
Chemical formula
C6H4(CH3)2
Isomers

ortho-xylene  meta-xylene  para-xylene
Molar weight
106
Conversion*
1 ppm = 4.34 mg/m3
Boiling point
144.4 °C
139 °C
138.35 °C
Low explosive limit (LEL), % vol.     
in air
0.9 - 1.1
Upper explosive limit (UEL), % vol.     
in air
6.0–7.0
Odor
Characteristic “chemical” smell
Hazards
Flammable.
Inhaling can cause dizziness, headache, drowsiness, and nausea.
Exposure limits 
according to 
Commission
Directive
2000/39/EC
TWA
8 hours
221 mg/mm3 / 50 ppm
STEL
15 minutes
442 mg/mm3 / 100 ppm

E2638-PID Rev 10.03.2021
Specifications
10
Detected gases
VOCs with ionisation potential < 10.6 eV
Sampling method
Diffusion
Sensor type
Photoionization detector
Calibration
Isobutylene
Order code
E2608-PID-40
E2608-PID-200
Typical detection
ranges
0...40 ppm (isobutylene)
0...200 ppm (isobutylene)
Resolution / digital unit
1 ppb
1 ppm
Response time T90
< 3 s
Sensor lifetime
5 years
Calibration interval
Monthly or more frequently depending on operating conditions
Signal update
Every 1 second
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
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
Outputs assignment
OUT1 gas; OUT2 gas
NOTE! for LCD version only output 1 is available
Output scale width
> 10 × resolution
Recommended: 20-100% of the detection range
Relay outputs
2 × SPST, max 5 A, 30 VDC / 250 VAC
Alarm setpoints
Determined by the user within 5-95% of the detection range
Cable connections
Screwless spring-loaded terminals
Enclosure
Grey ABS, wall mount, protection class IP65
Dimensions
H90 × W145 × D55 mm
(overall dimensions H140 × W145 × D55 mm)

E2638-PID Rev 10.03.2021
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
11
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
-40...+65ºC; 0,9...1,1 atm
15...90% RH non-condensing,
Explosion safe indoor areas, Non-aggressive atmosphere
Relay option
Relay outputs
2 × SPST relays (closing contact),
250 VAC / 30 VDC, 5 A max
Alarm setpoints
Determined by user within 5-95% of the detection range
Signalling options
Visual
Red and green LED
Acoustic alarm
Buzzer 85 dB
LCD indicator option
Operating temperature
0...+50 °C
Display dimensions
72 × 36 mm
Number of digits
3.5, digit 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-PID 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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12

E2638-PID 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.),
●Solvent vapors are heavier than air, so the gas detector-transmitter should be           
placed near the floor or potential leakage or formation 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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13

E2638-PID Rev 10.03.2021
Mounting dimensions


Front view



Bottom view
 
14

E2638-PID 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.

A) Wall mount remote probe with fixing clamp (default version),
B) Remote probe with rubber flange and three self-tapping screws (on request)

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 PID sensor from the device,
5. Insert the new PID sensor inside,
6. Put back the O-ring rubber, PTFE filter, and the head cap, respectively.
15

E2638-PID 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.



Version with PSU and relays Version with PSU and without relays




 
Version without PSU and with relays Version without PSU and relays
16

E2638-PID 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.

 
17

E2638-PID Rev 10.03.2021
Operation
Turn on the power. The instrument warm-up time takes ≤1 minute after switching on and              
the final sensor stabilization time to maximum accuracy takes <5 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.
 
18
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-PID Rev 10.03.2021
PID (photoionization detector) technology
The gas under investigation diffuses into the sensor’s testing cell, equipped with a source             
of high energy UV light (10.6 eV Krypton lamp) and electrodes. Exposed to UV light, organic               
molecules decompose to form ions, which are attracted by the electrodes. The measured            
resulting current is proportional to the VOC concentration.
Properties of VOC: ionization energy, the correction factor
Sensors used in E2638-PID are calibrated using isobutylene, but the PID is a broadband             
VOC detector, with a sensitivity that differs for each VOC. If you know what VOC you are                
measuring, then the table below will allow you to calculate the concentration for your             
specific VOC. Only the most common substances are listed in the table, if you can’t find               
your compound of concern, please contact us.
NOTE! These are approximate values, so for the best accuracy, you should calibrate with             
the relevant VOC.
The table includes the following columns:
1. The most common name for the VOC or other substances,
2. CAS No; You can find the VOC using the CAS No,
3. Brutto-formula,
4. Ionization energy (IE), (eV)
5. Relative Response/ Correction Factor (CF), Also called the Response Factor (RF).          
Multiply the displayed concentration by the Relative Response/CF/RF to calculate         
the actual concentration of the VOC.
6. Minimum Detection Level (MDL) Also called Minimum Detectable Quantity (MDQ).         
The typical lowest concentration that can be detected. The sensor used in           
E2638-PID-40 has greater sensitivity than that in E2638-PID-200, so the MDL for           
the E2638-PID-40 will be much less than the MDL for the E2638-PID-200.
The Relative Response/CF/RF is measured in dry air; high humidity will reduce this factor             
by 30% to 50%, so the CF/RF should be increased in high humidities. Relative sensitivity is               
the inverse of the correction factor, specifying the percent response of the VOC, relative to              
isobutylene. If less than 100%, then the VOC is less responsive than isobutylene; if the              
relative sensitivity is greater than 100%, then the VOC is more responsive than isobutylene.             
Relative sensitivity (%) is specified in the same way as cross-sensitivity for toxic gas             
sensors.
 
19

E2638-PID Rev 10.03.2021
VOC response
The PID can not measure all VOCs or gases, two types of VOCs are not measured:
NR: No response. The lamp does not ionize the VOC and the VOC cannot be measured.
NV: The vapor pressure of the VOC at 20°C is less than a few ppm, so this Semi-Volatile                 
Organic Compound (SVOC) cannot be measured.
NA: Not available
Occasionally you will be measuring a mixture of VOCs. If the total concentration is within              
the linear range of your PID, then it is reasonable to assume that the concentrations are               
additive without interference between the different VOCs. Remember that if you are           
measuring a combination of VOCs, then the accurate measurement of one of these VOCs             
will be difficult; without careful data analysis, you will get only a CF averaged             
measurement. Be cautious when reporting actual VOC concentration if you know that there            
may be several VOCs present.
Balance gas
The relative response is measured in laboratory air, with 20.9% oxygen, balanced nitrogen.            
Some gases absorb UV light without causing any PID response (e.g. methane, ethane). In             
ambient atmospheres where these gases are present, the measured concentration of          
target gas will be less than is actually present.
Methane absorbs UV strongly, so for accurate measurements in methane containing          
atmospheres, calibrate with a calibration gas containing the expected methane         
concentration. 50% of LEL methane reduces the reading by up to 50%. Gases such as              
nitrogen and helium do not absorb UV and do not affect the relative response.
The correction factor for a gas mix containing PID detectable gases A, B, C… with response               
factors RF(A), RF(B), RF(C), in relative proportions a: b: c… is given by:
CF(mix) = 1 / [(a/CF(A) + b/CF(B) + c/CF(C)…]
Accuracy of the Table: This table is for indication only. Table accuracy is 1 to 2 digits only,                 
so when calculating concentration for a specific VOC, only specify to 1 or 2 digits.
20
Index
Chemical name
Alternative name
Formula
CAS no.
IE, eV
Response
Factor (RF)
10.6 eV
E2638-
PID-40
(ppb)
E2638-
PID-200
(ppb)
1
Acetaldehyde

C2H4O
75-07-0
10.23
5.5
25
480
2
Acetamide

C2H5NO
60-35-5
9.69
2


3
Acetic acid

C2H4O2
64-19-7
10.66
28
180
3615
4
Acetic anhydride

C4H6O3
108-24-7
10.14
4
20
400