detcon inc.
Detcon Model Series
PI-600
Explosion Proof PID-Based Universal VOC Gas Sensors
(Also covers Model PI-601)
Operator’s Installation & Instruction Manual
December 17, 2009 • Document #2970 • Version 1.6
phone 888-367-4286, 713-559-9200 • fax 281-292-2860 • www.detcon.com • sales@detcon.com
Table of Contents
3.0 Description
3.1 Principle of Operation
3.2 Application
3.3 Specifications
3.4 Installation
3.5 Start-up
3.6 Operating Software & Magnetic Interface
3.7 Software Flow Chart
3.8 Calibration and Plug-in Sensor Maintenance
3.9 Status of Programming: Software Version, Calibration Level, and Sensor Life
3.10 Programming Alarms
3.11 Program Features
3.12 Display Contrast Adjust
3.13 Universal Transmitter Feature (Re-Initialization)
3.14 RS-485 Protocol
3.15 Trouble Shooting Guide
3.16 Spare Parts List
3.17 Warranty
3.18 Service Policy
PI-600 Toxic Gas Sensors PG.2
3.0 DESCRIPTION
Detcon MicroSafe™ Model PI-600 and PI-601 universal VOC sensors are non-intrusive “Smart” sensors designed to
detect and monitor for VOC & toxic gas in the ppm range. One of the primary features of the sensor is its method of
automatic calibration which guides the user through each step via instructions displayed on the backlit LCD. The sensor features LED indicators for 2 ALARMS, FAULT and CAL status; field adjustable, fully programmable alarms and
provides relays for two alarms plus fault as standard. The sensor comes with two different outputs: analog 4-20 mA, and
serial RS-485. These outputs allow for greater flexibility in system integration and installation. The microprocessor
supervised electronics are packaged as a universal plug-in transmitter module that mates to a standard connector board.
Both are housed in an explosion proof condulet that includes a glass lens. A 16 character alpha/numeric indicator is
used to display sensor readings as well as the sensor’s menu driven features via a hand-held programming magnet.
Typical ranges of detection are 0-10ppm, 0-20ppm, 0-50ppm, (using the PI-600) and 0-100ppm, 0-500ppm, and 01,000ppm (using the PI-601). Other ranges are available and all ranges are covered by this manual. To determine sensor
model number, reference the label located on the enclosure cover. To determine primary range, reference labeling on
the sensor head.
3.0.1 Sensor Technology
The sensors are based on a plug-in replaceable miniature PID (Photo-Ionization Detector) sensor technology. The sensor is sensitive to all ambient gases that have ionization potentials of < 10.6 eV, making it highly sensitive but extremely
non-specific. The sensor responds to most all toxic VOC compounds and many other toxic gases as well. The sensor is
comprised of a UV emitting lamp that is covered by a specific optical filter which projects only radiation in the 10.6 eV
range. Target gases that diffuse into the sensor chamber with ionization potentials of < 10.6 eV, are ionized by the radiation and give up free electrons. The free electrons are captured by the high voltage collection grid and provide a current signal that is directly proportional to the concentration of the target gas.
Target VOC Compounds
Membrane Filter
V
Construction of
PID Sensor
o+
e-
e- A
Collection Plates
UV Filter Window @ 10.6eV
Krypton
Gas
V
PI-600 Toxic Gas Sensors PG.3
Electrodeless Lamp Illumination Contacts
3.0.2 Universal Microprocessor Control Transmitter Circuit
The control circuit is microprocessor based and is packaged as a universal plug-in field replaceable module, facilitating
easy replacement and minimum down time. The universality includes the ability to set it for any range concentration
and for any gas type. These gas and range settings must be consistent with the PID Sensor Head it is mated with.
Circuit functions include a basic sensor pre-amplifier, on-board power supplies, microprocessor, back lit alpha numeric
display, fault, alarm, and calibration status LED indicators, magnetic programming switches, an RS-485 communication
port and a linear 4-20 mA DC output.
Program Switch #1
Plug-in Universal Microprocessor
Control Circuit
CONTRAST
PGM
Display Contrast Adjust
1
detcon inc.
MODEL
HOUSTON, TEXAS
0
PI-600
PPM VOC
Menu Driven Display
MicroSafe™ Gas Sensor
FLT
ALM ALM
2 CAL
1
PGM
2
Alarm & Cal LEDs
UNIVERSAL
TRANSMITTER
Program Switch #2
3.0.3 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 and lugless terminals for all field wiring.
Alarm Dry Contacts
FAULT ALM-2 ALM-1
NO/NC
COM
NO/NC
COM
NO/NC
COM
Optional 4-20 mA
Signal Developing Resistor
Use 250 ohm 1/4w
R1
ALARM 1
NC
NO
ALARM 2
NC
NO
VDC Power In
RS-485 In
RS-485 Out
MA
A
B
A
B
Jumper Programmable Alarm Outputs
Normally Open or Normally Closed
NC
NO
UN-USED
FAULT
WHT
BLK
YEL
BLU
4-20 mA Output
JUMPERS
Place un-used alarm programming
jumper tabs here
Sensor
3.0.4 Explosion Proof Enclosure
The transmitter electronics are 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 face plate are
activated through the lens window via a hand-held magnetic programming tool allowing non-intrusive operator interface
with the sensor. Calibration can be accomplished without removing the cover or declassifying the area. Electrical classification is Class I; Groups B, C, D; Division 1 (explosion proof).
Transmitter Electronics
in Explosion-Proof housing
PID Sensor Head
PI-600 Toxic Gas Sensors PG.4
3.1 PRINCIPLE OF OPERATION
Ionizable target gases diffuse into the PID sensor chamber through a sintered flame arrestor. These target gases are
exposed to UV radiation emitted by the PID lamp and this causes a fraction of the molecules to give up a free electron.
The free electrons are captured by the high voltage collection grid and provide a current signal that is directly proportional to the concentration of the target gas. This change in current is completely reversible and results in the continuous monitoring of ambient air conditions.
Pre-Amp
Display
Relays Out
Functional
Block
Diagram
Sensor
Element
Temperature
Compensation
Microprocessor
Alarm & Fault
Relays
Serial RS-485 Out
I/O Circuit
Protection
RS-485 & 4-20mA
Analog 4-20 mA Out
Power In
Transmitter
Power Supply
3.2 APPLICATION
3.2.1 Sensor Placement/Mounting
Sensor location should be reviewed by facility engineering and safety personnel. Area leak sources and perimeter mounting
are typically used to determine number and location of sensors. The sensors are generally located 2 - 4 feet above grade.
3.2.2 Interference Data
Detcon Model PI-600 series PID sensors are subject to interference from many gases. This interaction is shown in the
table in Section 3.2.3. The table shows most all gases of interest and the level of signal response they have relative to a
standard isobutylene reference gas. This measure is referred to as the Response Factor (RF). As a general rule, the lower
the RF value, the stronger the signal from the PID sensor. When determining a cross-interference from one gas to
another, find the RF of your target gas and then your interfering gas(es). The cross-interference will be calculated by
dividing the RF of your interfering gas by the RF of your target gas.
For example, if your target gas is benzene and you are concerned about a cross-interference to H2S then you would calculate the cross interference to be 3.3/0.50 = 6.2. This shall be interpreted as: it will take 6.2 ppm of H2S to register as
1 ppm benzene on a PID sensor calibrated for benzene.
In many cases, the user will be interested in measuring a multiple of toxic VOC compounds. In this case the sensor
will produce a signal that is a composite total of each gases’ individual response, when taking into account the corresponding response factors.
For example, if the target gases are benzene and isobutanol and your PID sensor was calibrated for benzene then the
presence of 5 ppm benzene and 5 ppm of isobutanol would each add to the total reading. In this case, the 5 ppm benzene would register as 5 ppm, but the 5 ppm isobutanol would register as the amount of cross interference of isobutanol relative to a benzene calibration. This is calculated as discussed above where you divide the RF of isobutanol by
the RF of benzene. Using the look up table this gives you 3.8/0.50 = 7.2. So it takes 7.2 ppm isobutanol to equal 1
part benzene. Since we have 5 ppm isobutanol, that will equal 0.7 ppm on the benzene scale. The total signal will be 5
+ 0.7 = 5.7 ppm.
3.2.3 Relative Response Gas Matrix (See next page)
The table shows you the response of the PID sensor to a long list of components. It includes the compound name,
synonyms/abbreviations, and chemical formula. It also lists the 10.6 eV Response Factor (the measure of how strong
the signal from the sensor is in reference to Isobutylene gas). Isobutylene gas is the standard reference used with PID
sensors, the lower the Response Factor, the stronger the signal.
NR = not reccomended (does not register)
? = measureable but no data exist
Confirmed Value = “+” means actual gas has been used to verify RF, “blank” means it is an empirical estimate
IP = is the gases ionization potential (only gases < 10.6eV will respond to sensor)
TWA/Time Weighted Average = generally accepted limit for safe 8 hour exposure (in ppm)
PI-600 Toxic Gas Sensors PG.5
3.2.3 Relative Response Gas Matrix (page 1 of 8)
Compound Name
10.6 eV
Response Factor
Confirmed Value
IP (eV)
TWA
C2H4O
5.5
+
10.23
C25
C2H4O2
22
+
10.66
10
C4H6O3
6.1
+
10.14
5
C3H6O
1.1
+
9.71
500
Synonym/Abbreviation
Formula
Acetic Acid
Ethanoic Acid
Acetic Anhydride
Ethanoic Acid Anhydride
Acetone
2-Propanone
Acetaldehyde
Acetonitrile
Methyl cyanide, Cyanomethane
C2H3N
NR
12.19
40
Acetylene
Ethyne
C2H2
NR
11.40
ne
Acrolein
Propenal
C3H4O
3.9
+
10.10
0.1
Acrylic Acid
Propenoic Acid
C3H4O2
12
+
10.60
2
Acrylonitrile
Propenenitrile
C3H3N
NR
+
10.91
2
C3H6O
2.4
+
9.67
2
C3H5Cl
4.3
9.9
1
H3N
9.7
10.16
25
C5H12O
5
10.00
100
7.72
2
8.21
ne
9.89
0.05
9.49
ne
9.25
0.5
9.62
ne
Allyl alcohol
Allyl chloride
3-Chloropropene
Ammonia
Amyl alcohol
mix of n-pentyl acetate &
2-Methylbutyl acetate
Aniline
Aminobenzene
C7H7N
0.5
Anisole
Methoxybenzene
C7H8O
0.8
Arsine
Arsenic trihydride
AsH3
1.9
C7H6O
?
Benzaldehyde
Benzene
+
+
+
C6H6
0.5
Benzonitrile
Cyanobenzene
C7H5N
1.6
Benzyl alcohol
a-Hydroxytoluene,
Hydroxymethylbenzene,
Benzenemethanol
C7H8O
1.1
+
8.26
ne
Benzyl chloride
a-Chlorotoluene,
Chloromethylbenzene
C7H7Cl
0.6
+
9.14
1
Benzyl formate
Formic acid benzyl ester
C8H8O2
0.73
+
Boron trifluoride
BF3
NR
Bromine
Br3
1.30
Bromobenzene
C6H5Br
0.6
2-Bromoethyl methyl ether
C3H7OBr
0.84
+
ne
15.5
C1
10.51
0.1
8.98
ne
+
~10
ne
+
Bromoform
Tribromomethane
CHBr3
2.5
+
10.48
0.5
Bromopropane, 1-
n-Propyl bromide
C3H7Br
1.5
+
10.18
ne
Butadiene
1,2-Butadiene, Vinyl ethylene
C4H6
0.85
+
9.07
2
Butadiene diepoxide, 1, 3-
1,2,3,4-Diepoxybutane
C4H6O2
3.5
+
~10
ne
C4H10
67
10.53
ne
Butanol, 1-
Butane
Butyl alcohol, n-Butanol
C4H10O
4.7
+
9.99
C50
Butanol, t-
tert-butanol, t-Buty alcohol
C4H10O
2.9
+
9.90
100
Butene, 1-
1-Butylene
C4H8
0.9
9.58
ne
Butoxyethanol, 2-
Butyl Cellosolve,
Ethyleneglycol monobutyl ether
C6H14O2
1.2
+
<10
25
C6H12O2
2.6
+
10
150
C7H12O2
1.6
+
Butyl acetate, nButyl acrylate, n-
Butyl 2-propenoate,
Acrylic acid butyl ester
Butylamine
C4H11N
7
Butylamine, n-
C4H11N
1.1
PI-600 Toxic Gas Sensors PG.6
10
8.71
+
8.71
C5
3.2.3 Relative Response Gas Matrix (page 2 of 8)
Compound Name
Synonym/Abbreviation
Butyl cellosolve
see 2-Butoxyethanol
Butyl hydroperoxide, tButyl mercaptan
1-Butanethiol
Carbon disulfide
Carbon monoxide
Formula
10.6 eV
Response Factor
Confirmed Value
IP (eV)
TWA
C4H10O2
1.6
+
<10
1
C4H10S
0.52
+
9.14
0.5
CS2
1.2
+
10.07
10
CO
NR
+
14.07
50
Carbon tetrachloride
Tetrachloromethane
CCl4
NR
+
11.47
5
Carbonyl sulfide
Carbon Oxysulfide
COS
NR
11.18
Chlorine
Cl2
NR
11.48
0.5
Chlorine dioxide
ClO2
NR
+
10.57
0.1
+
9.06
10
Cellosolve see 2-Ethoxyethanol
CFC-14 see Tetrafluoromethane
CFC-113 see 1,1,2-Trichloro-1,2,2-trifluoroethane
Chloro-1,3-butadiene, 2-
Chloroprene
C4H5Cl
3
Chlorobenzene
Monochlorobenzene
C6H5Cl
0.40
Chloro-1, 1-difluoroethane, 1-(R-142B)
C2H3ClF2
NR
12.0
Chlorodifluoromethane
CHClF2
NR
12.2
NR
HCFC-22, R-22
Chloroethane
Ethyl chloride
C2H5Cl
Chloroethanol
Ethylene chlorhydrin
C2H5ClO
Chloroethyl ether, 2-
bis(2-chloroethyle) ether
C4H8Cl2O
3.0
Chloroethyl methyl ether,2-
Methyl 2-chloroethyl ether
C3H7ClO
3
Chloroform
Trichloromethane
Chloropicrin
10
+
1000
10.97
100
10.52
C1
+
5
ne
CHCl3
NR
+
11.37
10
CCl3NO2
~400
+
?
0.1
Chlorotoluene, o-
o-Chloromethylbenzene
C7H7Cl
0.5
8.83
50
Chlorotoluene, p-
p-Chloromethylbenzene
C7H7Cl
0.5
8.69
ne
Crotonaldehyde
trans-2-Butenal
C4H6O
1.1
+
9.73
2
Cumene
Isopropylbenzene
C9H12
0.54
+
8.73
50
Cyanogen bromide
CNBr
NR
11.84
ne
Cyanogen chloride
CNCl
NR
12.34
C0.3
Cyclohexane
C6H12
1.4
C6H12O
?
Cyclohexanone
C6H10O
0.9
Cyclohexene
C6H10
0.8
Cyclohexanol
Cyclohexyl alcohol
+
9.86
300
9.75
50
+
9.14
25
+
8.95
300
Cyclohexylamine
C6H13N
1.2
8.62
10
Cyclopentane
C5H10
1.4
10.51
600
Decane
C10H22
1.4
9.65
ne
+
Diacetone alcohol
4-Methyl-4-hydroxy-2- pentanone
C6H12O2
0.7
50
Dibromoethane,1,2-
EDB, Ethylene dibromide,
Ethylene bromide
C2H4Br2
1.7
+
10.37
Dichlorobenzene, o
1,2-Dichlorobenzene
C6H4Cl2
0.47
+
9.08
Dichlorodifluoromethane
CFC-12
CCl2F2
NR
+
11.75
C2H4Cl2
NR
Dichloroethane, 1,1Dichloroethane, 1,2-
EDC, 1,2-DCA, Ethylene dichloride
C2H4Cl2
NR
Dichloroethene, 1,1-
1,1-DCE, Vinylidene chloride
C2H2Cl2
0.9
PI-600 Toxic Gas Sensors PG.7
ne
1000
11.06
+
11.04
10
9.79
5
3.2.3 Relative Response Gas Matrix (page 3 of 8)
Compound Name
Synonym/Abbreviation
Formula
10.6 eV
Response Factor
Confirmed Value
IP (eV)
TWA
9.66
200
9.65
200
Dichloroethene, c-1,2-
c-1,2-DEC, cis-Dichloroethylene
C2H2Cl2
0.8
Dichloroethene, t-1,2-
t-1,2-DCE, trans-Dichloroethylene
C2H2Cl2
0.45
+
Dichloro-1-fluoroethane, 1,1-
R-141B
C2H3Cl2F
NR
+
ne
C3HCl2F5
NR
+
ne
Dichloropropane, 1,2
C3H6Cl2
NR
Dichloro-1-propene, 1,3-
C3H4C12
0.96
+
<10
1
Dichloro-1-propene, 2,3-
C3H4Cl2
1.3
+
<10
ne
Dichloromethane (see Methylene chloride)
Dichloropentafluoropropane
AK-255, mix of ~45% 3,3- dichloro1,1,1,2,2-pentafluoro- propane
(HCFC-225ca) & ~55% 1,3-Dichloro1,1,2,2,3- pentafluoropropane
(HCFC-225cb)
10.87
75
Dichloro-1,1,1-trifluoro
-ethane, 2,2-
R123
C2HCl2F3
NR
+
11.5
ne
Dichlorvos
Vapona; O,O-dimethyl Odichlorovinyl phospate
C4H7Cl2O4P
0.9
+
<9.4
0.1
Dicyclopentadiene
DCPD, Cyclopentadiene dimer
C10H12
0.5
+
8.8
5
Diesel Fuel #1
m.w. 226
0.9
+
Diesel Fuel #2
m.w. 216
0.7
+
+
8.01
5
Diethylamine
C4H11N
1
Diethylaminopropylamine, 3-
C7H18N2
1.3
Diethylmaleate
C8H12O4
4
Diethyl sulfide
ne
see Ethyl sulfide
Diisopropylamine
C6H15N
0.74
+
7.73
5
Diketene
Ketene dimer
C4H4O2
2.0
+
9.6
0.5
Dimethylacetamide, N,N-
DMA
C4H9NO
0.8
+
8.81
10
C2H7N
1.5
8.23
5
Dimethylamine
Dimethyl disulfide
C2H6S2
0.20
+
7.4
Dimethyl carbonate
Carbonic acid dimethyl ester
C3H6O3
~70
+
~10.5
ne
Dimethyl disulfide
DMDS
C2H6S2
0.20
+
7.4
ne
Dimethylethylamine
DMEA
C4H11N
1.0
+
7.74
~3
Dimethylformamide, N,N-
DMF
C3H7NO
0.8
9.13
10
Dimethylhydrazine, 1,1-
UDMH
C2H8N2
0.8
+
7.28
0.01
Dimethyl methylphosphonate
DMMP, methyl phosphonic acid
dimethyl ester
C3H9O3P
4.3
+
10.0
ne
C2H6O4S
~20
+
C2H6OS
1.4
+
C4H8O2
1.3
Dimethyl sulfate
Dimethyl sulfide
see Methyl sulfide
Dimethyl sulfoxide
DMSO, Methyl sulfoxide
Dioxane, 1,4-
0.1
9.10
ne
9.19
25
Dowtherm A see Therminol
DS-108F Wipe Solvent
Ethyl lactate/Isopar H/
Propoxypropanol ~7:2:1
m.w. 118
1.6
+
Epichlorohydrin
ECH Chloromethyloxirane, 1chloro2,3-epoxypropane
C2H5ClO
8.5
+
10.2
0.5
C2H6
NR
+
11.52
ne
C2H6O
12
+
10.47
1000
Ethane
Ethanol
Ethyl alcohol
PI-600 Toxic Gas Sensors PG.8
ne
3.2.3 Relative Response Gas Matrix (page 4 of 8)
Compound Name
Synonym/Abbreviation
Ethanolamine (not recommended) MEA, Monoethanolamine
Formula
C2H7NO
10.6 eV
Response Factor
1.6
Confirmed Value
+
IP (eV)
8.96
TWA
3
Ethene
Ethylene
C2H4
10
+
10.51
ne
Ethoxyethanol, 2-
Ethyl cellosolve, Ethylene glycol
monoethyl ether
C4H10O2
1.3
9.6
5
Ethyl acetate
C4H8O2
4.6
+
10.01
400
Ethyl acrylate
C5H8O2
2.4
+
(<10.3)
5
Ethylamine
C2H7N
0.8
8.86
5
Ethylbenzene
C8H10
0.52
+
8.77
100
10.16
C100
Ethylene glycol
1,2-Ethanediol
C2H6O2
16
+
Ethylene oxide
Oxirane, Epoxyethane
C2H4O
13
+
Ethyl ether
Diethyl ether
C4H10O
1.1
+
Ethyl 3-ethoxypropionate
EEP
C7H14O3
1.0.75
+
C3H6O2
?
Ethyl formate
10.57
1
9.51
400
ne
10.61
100
Ethyl hexyl acrylate, 2-
Acrylic acid 2-ethylhexyl ester
C11H20O2
1.1
+
ne
Ethyl (S)-(-)-lactate see also
DS-108F
Ethyl lactate, Ethyl (S)-(-)hydroxypropionate
C5H10O3
3.2
+
~10
ne
Ethyl mercaptan
Ethanethiol
C2H6S
0.56
+
9.29
0.5
Ethyl sulfide
Diethyl sulfide
C4H10S
0.5
+
8.43
ne
Formaldehyde
Formalin
CH2O
NR
10.87
C0.3
CH2O2
NR
+
11.33
5
Formic acid
C5H4O2
0.92
+
9.21
2
Furfuryl alcohol
Furfural
2-Furaldehyde
C5H6O2
0.80
+
<9.5
10
Gasoline #1
m.w. 72
0.9
+
300
Gasoline #2, 92 octane
m.w. 93
1.0
+
300
0.8
+
Glutaraldehyde
1,5-Pentanedial, Glutaric dialdehyde
Halothane
2-Bromo-2-chloro-1,1,1- trifluoroethane C2HBrClF3
C5H8O2
NR
C0.0
11.0
50
400
HCFC-22 (see Chlorodifluoromethane)
HCFC-123 (see 2,2-Dichloro-1,1,1-trifluoroethane, R-123)
HCFC-141B (see 1,1-Dichloro-1-fluorethane)
HCFC-142B (see 1-Chloro-1,1-difluoroethane)
HCFC-134A (see 1,1,1,2-Tetrafluoroethane)
HCFC-225 (see Dichloropentafluoropropane)
Heptane, n-
C7H16
2.8
+
9.92
Hexamethyldisilazane,1,1,1,3,3,3- HMDS
C6H19NSi2
0.2
+
~8.6
Hexane, n
C6H14
4.3
+
10.13
Hexane, 1-
C6H12
9.44
Hexanol, 1-
C6H14O
2.5
Hexene, 1-
Hexyl alcohol
C6H12
0.8
+
Hydrazine
H4N2
2.6
+
8.1
50
9.86
ne
9.44
30
Hydrogen
Synthesis gas
H2
NR
+
15.43
ne
Hydrogen cyanide
Hydrocyanic acid
HCN
NR
+
13.60
C4.7
Hydrogen peroxide
H2O2
NR
+
10.54
1
Hydrogen sulfide
H2S
3.3
+
10.45
10
PI-600 Toxic Gas Sensors PG.9
3.2.3 Relative Response Gas Matrix (page 5 of 8)
Compound Name
10.6 eV
Response Factor
Synonym/Abbreviation
Formula
I2
0.1
+
9.40
C0.1
Iodomethane
Methyl iodide
CH3I
0.2
+
9.54
2
Isoamyl acetate
Isopentyl acetate
C7H14O2
2.1
<10
100
Isobutne
2-Methylpropane
C4H10
100
10.57
ne
Iodine
Confirmed Value
+
IP (eV)
TWA
Isobutanol
2-Methyl-2-propanol
C4H10O
3.8
+
10.02
50
Isobutylene
Isobutxene, Methyl butene
C4H8
1.00
+
9.24
ne
C6H12O2
2.60
Isobutyl acetate
150
Isobutyl acrylate
Isobutyl 2-propenoate, Acrylic acid
Isobutyl ester
C7H12O2
1.5
+
ne
Isoflurane
1-Chloro-2,2,2-trifluoroethyl
difluoromethyl ether, forane
C3H2ClF5O
NR
~11.7
ne
Isooctane
2,2,4-Trimethylpentane
C8H18
1.2
9.86
ne
Isopar E Solvent
Isoparaffinic hydrocarbons
m.w. 121
0.8
+
ne
Isopar G Solvent
Photocopier diluent
m.w. 148
0.8
+
ne
Isopar K Solvent
Isoparaffinic hydrocarbons
m.w. 156
0.5
+
ne
Isopar L Solvent
Isoparaffinic hydrocarbons
m.w. 163
0.5
+
Isopar M Solvent
Isoparaffinic hydrocarbons
m.w. 191
0.7
+
Isopentane
2-Methylbutane
Isophorone
C5H12
8.2
C9H14O
?
ne
9.07
C5
Isoprene
2-Methyl-1,3-butadiene
C5H8
0.63
+
8.85
ne
Isopropanol
Isopropyl alcohol, 2-propanol
C3H8O
6.0
+
10.12
400
C5H10O2
2.6
9.99
250
Isopropyl ether
Diisopropyl ether
C6H14O
0.8
9.20
250
Jet fuel JP-4
Jet B, Turbo B, Wide cut type aviation fuel m.w. 115
1.0
+
ne
Jet fuel JP-5
Jet 5, Kerosene type aviaton fuel
m.w. 167
0.6
+
15
Isopropyl acetate
Jet fuel JP-8
Jet A-1, Kerosene type aviation fuel
m.w. 165
0.6
+
Limonene, D-
(R)-(+)-Limonene
C10H16
0.33
+
15
~8.2
ne
Kerosene (C10-C16 petro.distillate - see Jet Fuels)
MDI (see 4,4'-Methylenebis(phenylisocynate))
Mesitylene
1,3,5-Trimethylbenzene
C9H12
0.35
+
8.41
ne
Methane
Natural gas
CH4
NR
+
12.51
ne
Methanol
Methyl alcohol, carbinol
CH4O
NR
+
10.85
200
Methoxyethanol, 2-
Mehtyl cellosolve, Ethylene glycol
monomethy ether
C3H8O2
2.4
+
10.1
5
Methoxyethoxyethanol, 2-
2-(2-Methoxyethoxy)ethanol
Diethylene glycol monomethyl ether
C7H16O3
1.2
+
<10
ne
C3H6O2
6.6
+
10.27
200
+
(9.9)
2
Methyl acetate
Methyl acrylate
Methyl 2-propenoate, acrylic acid
methyl ester
C4H6O2
3.7
Methylamine
Aminomethane
CH5N
1.2
Methyl bromide
Bromomethane
CH3Br
1.7
+
10.54
1
Methyl t-butyl ether
MTBE, tert-Butyl methyl ether
C5H12O
0.9
+
9.24
40
CH3Cl
NR
+
11.22
50
C7H14
0.97
+
9.64
400
8.97
Methyl cellosolve (see 2-Methoxyethanol)
Methyl chloride
Methylcyclohexane
Chloromethane
PI-600 Toxic Gas Sensors PG.10
3.2.3 Relative Response Gas Matrix (page 6 of 8)
Compound Name
Synonym/Abbreviation
Formula
Methylene bis(phenylMDI, Mondur M
isocyanate), 4,4'-Methylene chloride
10.6 eV
Response Factor
Confirmed Value
IP (eV)
C15H10N2O2
Very slow ppb level response
Dichloromethane CH2Cl2 NR
+
TWA
0.005
11.32 25
Methyl ether
Dimethyl ether
C2H6O
3.1
+
10.03
ne
Methyl ethyl ketone
MEK, 2-Butanone
C4H8O2
0.9
+
9.51
200
Methylhydrazine
Monomethylhydrazine,
Hydrazomethane
C2H6N2
1.2
+
7.7
0.01
Methyl isobutyl ketone
MIBK, 4-Methyl-2-pentanone
C6H12O
0.8
+
9.30
50
Methyl Isocyanate
CH3NCO
C2H3NO
4.6
+
10.67
0.02
Methyl isothiocyanate
CH3NCS
C2H3NS
0.45
+
Methyl mercaptan
Methanethiol
CH4S
0.54
C5H8O2
1.5
+
Methyl methacrylate
9.25
ne
9.44
0.5
9.7
100
Methyl nonafluorobutyl ether
HFE-7100DL
C5H3F9O
NR
+
ne
Methyl-1,5-pentane- diamine,
2- (coats lamp)
Dytek-A amine, 2-Methyl
pentamethylenediamine
C6H16N2
~0.6
+
<9.0
ne
Methyl propyl ketone
MPK, 2-Pentanone
C5H12O
0.93
+
9.38
200
Methyl-2-pyrrolidinone, N-
NMP, N-Methylpyrrolidone, 1-Methyl- C5H9NO
2-pyrrolidinone, 1-Methyl-2-pyrrolidone
0.8
+
9.17
ne
Methyl salicylate
Methyl 2-hydroxybenzoate
C8H8O3
1
~9
ne
Methylstyrene, a-
2-Propenylbenzene
C9H10
0.5
8.18
50
Methyl sulfide
DMS, Dimethyl sulfide
C2H6S
0.44
+
8.69
ne
Mineral spirits (Stoddard
Solvent, see also Viscor 120B)
m.w. 144
0.7
+
100
Mineral spirits Viscor 120B
Calibration Fluid, b.p. 156-207°C
m.w. 142
0.7
+
100
Mustard
HD, Bis (2-chloroethyl) sulfide
C4H8Cl2S
0.6
Naphthalene
Mothballs
C10H8
0.42
+
8.13
10
NO
5.2
+
9.26
25
+
9.81
1
10.88
100
9.75
3
11.02
20
Nitric oxide
Nitrobenzene
C6H5NO2
1.9
Nitroethane
C2H5NO2
NR
Nitrogen dioxide
NO2
16.0
Nitromethane
CH3NO2
NR
0.0005
+
Nitropropane, 2-
C3H7NO2
NR
10.71
10
Nonane
C9H20
1.4
9.72
200
Octane, n-
C8H18
1.8
+
9.82
300
Pentane
C5H12
8.4
+
10.35
600
NR
+
ne
ne
Peracetic acid
Peroxyacetic acid, Acetyl
Hydroperoxide
C2H4O3
Peracetic/Acetic acid mix
Peroxyacetic acid, Acetyl
Hydroperoxide
C2H4O3/C2H4O2 50
+
Perchloroethene
PCE, Perchloroethylene,
Tetrachloroethylene
C2Cl4
0.57
+
PGME
Propylene glycol methyl ether, 10798-2 1-Methoxy-2-propanol
C6H12O3
1.5
+
100
PGMEA
Propylene glycol methyl ether 108
-65-6 acetate, 1-Methoxy-2acetoxypropane, 1-Methoxy-2propanol acetate
C6H12O3
1.0
+
ne
PI-600 Toxic Gas Sensors PG.11
9.32
25
3.2.3 Relative Response Gas Matrix (page 7 of 8)
Compound Name
Synonym/Abbreviation
Formula
10.6 eV
Response Factor
Confirmed Value
+
Phenol
Hydroxybenzene
C6H6O
1.0
Phosgene
Dichlorocarbonyl
CCl2O
NR
PH3
3.9
+
0.5
+
Phosphine in N2
Photocopier Toner
Isoparaffin mix
Picoline, 3-
3-Methylpyridine
IP (eV)
TWA
8.51
5
11.2
0.1
9.87
0.3
C6H7N
0.9
Pinene, a-
C10H16
0.31
+
8.07
ne
Pinene, b
C10H16
0.37
+
~8
100
1,3-Pentadiene
C5H8
0.69
+
8.6
100
C3H8
NR
+
Propanol, n-
Propyl alcohol
C3H8O
5
Propene
Propylene
C3H6
1.4
Propionaldehyde
Propanal
C3H6O
1.9
Piperylene, isomer mix
Propane
9.04
+
10.95
2500
10.22
200
9.73
ne
9.95
ne
Propyl acetate, n-
C5H10O2
3.5
10.04
200
Propylene carbonate
C4H6O3
62
+
10.5
ne
Propylene glycol
1,2-Propanediol
C3H8O2
5.5
+
<10.2
ne
Propylene oxide
Methyloxirane
C3H6O
6.6
+
10.22
20
Propyleneimine
2-Methylaziridine
C3H7N
1.3
+
9.0
2
Propyl mercaptan, 2-
2-Propanethiol, Isopropyl mercaptan
C3H7N
0.66
+
9.2
ne
C5H5N
0.7
+
9.25
5
C4H9N
~8.0
ne
Pyridine
Pyrrolidine (coats lamp)
Azacyclohexane
1.3
+
RR7300
70:30 PGME:PGMEA (1- Methoxy-2- C4H10O2 / C6H12O3 1.4
propanol:1- Methoxy-2-acetoxypropane)
+
(PGME/PGMEA)
Sarin
GB, Isopropyl
methylphosphonofluoridate
ne
C4H10FO2P
~3
Styrene
C8H8
0.40
+
8.43
Sulfur dioxide
SO2
NR
+
12.32
Sulfur hexafluoride
SF6
NR
15.3
1000
13.0
6
Stoddard Solvent - see Mineral Spirits
Sulfuryl fluoride
Vikane
SO2F2
NR
Tabun
Ethyl N, Ndimethylphosphoramidocyanidate
C5H11N2O2P
0.8
Tetrachloroethane, 1,1,1,2-
C2H2Cl4
NR
Tetrachloroethane, 1,1,2,2-
C2H2Cl4
NR
Tetraethyllead
TEL
C8H20Pb
0.3
Tetraethyl orthosilicate
Ethyl silicate, TEOS
C8H20O4Si
0.7
Tetrafluoroethane, 1,1,1,2-
HFC-134A
C2H2F4
NR
Tetrafluoroethene
TFE, Tetrafluoroethylene,
Perfluoroethylene
C2F4
~15
Tetrafluoromethane
CFC-14, Carbon tetrafluoride
CF4
NR
Tetrahydrofuran
THF
C4H8O
1.7
Tetramethyl orthosilicate
Methyl silicate, TMOS
C4H12O4Si
Therminol VP-1
Toluene
20
15ppt
+
+
~11.1
ne
~11.1
1
~11.1
0.008
~9.8
10
ne
10.12
ne
+
>15.3
ne
+
9.41
200
1.9
+
~10
1
Dowthern,3:1 Diphenyl oxide:
Biphenyl
C12H10O C12H10 0.7
+
Methylbenzene
C7H8
+
0.50
PI-600 Toxic Gas Sensors PG.12
ne
8.82
50
3.2.3 Relative Response Gas Matrix (page 8 of 8)
Compound Name
Synonym/Abbreviation
Formula
10.6 eV
Response Factor
Confirmed Value
Tolylene-2,4-diisocyanate
TDI, 4-Methyl-1,3-phenylene- 2,4diisocyanate
C9H6N2O2
1.4
+
IP (eV)
TWA
0.002
Trichlorobenzene, 1,2,4-
1,2,4-TCB
C6H3Cl3
0.46
+
9.04
C5
Trichloroethane, 1,1,1-
1,1,1-TCA, Methyl chloroform
C2H3Cl3
NR
+
11
350
Trichloroethane, 1,1,2-
1,1,2-TCA
C2H3Cl3
NR
+
11.0
10
Trichloroethene
TCE, Trichloroethylene
C2HCl3
0.54
+
9.47
50
Trichlorotrifluoroethane, 1,1,2CFC-113
CFC-113
C2Cl3F3
NR
11.99
1000
Triethylamine
TEA
C6H15N
0.9
+
7.3
1
Triethyl borate
TEB; Boric acid triethyl ester,
Boron ethoxide
C6H15O3B
2.2
+
~10
Triethyl phosphate
Ethyl phosphate
+
C6H15O4P
3.1
9.79
ne
Trifluoroethane, 1,1,2-
C2H3F3
NR
12.9
ne
Trimethylamine
C3H9N
0.9
7.82
5
Trimethylbenzene, 1,3,5- - (see Mesitylene)
25
Trimethyl borate
TMB; Boric acid trimethyl ester,
Boron methoxide
C3H9O3B
5.1
+
10.10
ne
Trimethyl phosphate
Ethyl phosphate
C3H9O4P
8.0
+
9.99
ne
Turpentine
Pinenes (85%) + other diisoprenes
C10H16
0.3
+
~8
100
C11H24
2
9.56
ne
C4H6O2
1.2
+
9.19
10
9.80
5
9.99
5
Undecane
Varsol (see Mineral Spirits)
Vinyl actetate
Vinyl bromide
Bromoethylene
C2H3Br
0.4
Vinyl chloride in N2
Chloroethylene, VCM
C2H3Cl
2.0
+
C6H9NO
0.8
+
C8H10
0.4
+
Vinylidene chloride - see 1,1-Dicholorethene
Vinyl-2-pyrrolidinone, 1-
NVP, N-vinylpyrrolidone, 1- ethenyl2-pyrrolidinone
ne
Viscor 120B - see Mineral Spirits - Viscor 120B Calibration Fluid
Xylene, m-
8.56
Xylene, o-
C8H10
0.6
+
8.56
Xylene, p-
C8H10
0.5
+
8.44
None
1
PI-600 Toxic Gas Sensors PG.13
3.3 SPECIFICATIONS
Method of Detection
Plug-in Miniature PID Sensor
Repeatability
± 2% FS
Response Time
T90 < 30 seconds
Temperature Range
0-50°C; 32-122°F
Humidity Range
0-99% RH noncondensing
Output
Linear 4-20 mA DC
3 Relays (Alarm 1, Alarm 2, and Fault) contacts rated 5A@ 150VAC, 5A @30 VDC
RS-485 Modbus™
Input Voltage
22-28 VDC
Power Consumption
Normal operation = 58 mA (1.4 watts @ 24VDC); Maximum = 128 mA (3.1 watts @ 24VDC)
Electrical Classification
Class 1; Groups B, C, D; Div. 1.
Sensor Warranty
12 Months
3.4 INSTALLATION
Optimum performance of ambient air/gas sensor devices is directly relative to proper location and installation practice.
3.4.1 Field Wiring Table (4-20 mA output)
Detcon Model PI-600 toxic gas sensor assemblies require three conductor connection between power supplies and host
electronic controllers. Wiring designators are + (DC), – (DC) , and mA (sensor signal). Maximum single conductor
resistance between sensor and controller is 10 ohms. Maximum wire size for termination in the sensor assembly terminal
board is 14 gauge.
AWG
20
18
16
14
Meters
240
360
600
900
Feet
800
1200
2000
3000
Note 1: This wiring table is based on stranded tinned copper wire and is designed to serve as a reference only.
Note 2: Shielded cable may be required in installations where cable trays or conduit runs include high voltage lines or
other sources of induced interference.
The RS-485 (if applicable) requires 24 guage, two conductor, shielded, twisted pair cable between sensor and host PC.
Use Belden part number 9841. Two sets of terminals are located on the connector to facilitate serial loop wiring from
sensor to sensor. Wiring designators are A & B (IN) and A & B (OUT).
3.4.2 Sensor Location
Selection of sensor location is critical to the overall safe performance of the product. Five factors play an important role
in selection of sensor locations:
(1)
(2)
(3)
(4)
(5)
Density of the gas to be detected
Most probable leak sources within the industrial process
Ventilation or prevailing wind conditions
Personnel exposure
Maintenance access
PI-600 Toxic Gas Sensors PG.14
Density - Placement of sensors relative to the density of the target gas is such that sensors for the detection of heavier than air
gases should be located within 2-4 feet of grade as these heavy gases will tend to settle in low lying areas. For gases lighter than
air, sensor placement should be 4-8 feet above grade in open areas or in pitched areas of enclosed spaces.
Leak Sources - Most probable leak sources within an industrial process include flanges, valves, and tubing connections
of the sealed type where seals may either fail or wear. Other leak sources are best determined by facility engineers with
experience in similar processes.
Ventilation - Normal ventilation or prevailing wind conditions can dictate efficient location of gas sensors in a manner
where the migration of gas clouds is quickly detected.
Personnel Exposure - The undetected migration of gas clouds should not be allowed to approach concentrated personnel areas such as control rooms, maintenance or warehouse buildings. A more general and applicable thought toward
selecting sensor location is combining leak source and perimeter protection in the best possible configuration.
Maintenance Access
Consideration should be given to easy access by maintenance personnel as well as the consequences of close proximity
to contaminants that may foul the sensor prematurely.
Note: In all installations, the sensor element in SS housing points down relative to grade (Fig. 1). Improper sensor orientation may result in false reading and permanent sensor damage.
Plug any unused ports.
“T”
Drain
EYS
Seal
Fitting
3.4.3 Local Electrical Codes
Sensor and transmitter assemblies should be installed in accordance with all local electrical codes. Use appropriate conduit seals. Drains & breathers are recommended. The sensor assemblies are suitable for Class I; Groups B, C, D; Div. 1
environments.
PI-600 Toxic Gas Sensors PG.15
3.4.4 Installation Procedure
a) Securely mount the sensor junction box in accordance with recommended practice. See dimensional drawing (Fig. 2).
b) Remove the junction box cover and un-plug the control circuit by grasping the two thumb screws and pulling outward.
4 3/4"
6 1/8"
5 1/2"
3/4" NPT
3/4" NPT
7 1/4"
1/4" Dia.
Mounting Holes
Rain
Shield
2 1/8"
2"
c) Observing correct polarity, terminate 3 conductor field wiring, RS-485 wiring, and applicable alarm wiring to the sensor
base connector board in accordance with the detail shown in Figure 3. Normally open and normally closed Form C dry
contacts (rated 5 amp @ 150VAC; 5 amp @ 30VDC) are provided for Fault, Alarm 1, and Alarm 2.
Note: Per U.L. approval, these relays may only be used in connecting to devices that are powered by the same voltages.
Figure 3
Alarm Dry Contacts
FAULT ALM-2 ALM-1
NO/NC
COM
NO/NC
COM
NO/NC
COM
Optional 4-20 mA
Signal Developing Resistor
Use 250 ohm 1/4w
R1
ALARM 1
NC
NO
ALARM 2
NC
NO
VDC Power In
RS-485 In
RS-485 Out
MA
A
B
A
B
NC
NO
UN-USED
FAULT
WHT
BLK
YEL
BLU
4-20 mA Output
Jumper Programmable Alarm Outputs
Normally Open or Normally Closed
JUMPERS
Place un-used alarm programming
jumper tabs here
Sensor
d) Position gold plated jumper tabs located on the connector board in accordance with desired Form C dry contact
outputs: NO = Normally Open; NC = Normally closed (see figure 3).
PI-600 Toxic Gas Sensors PG.16
Note: If a voltage signal output is desired in place of the 4-20mA output, a 1/4 watt resistor must be installed in position R1 of the terminal board. A 250Ω resistor will provide a 1-5V output (– to mA). A 100Ω resistor will provide a
.4-2V output, etc. This linear signal corresponds to 0-100% of scale (see figure 3).
e) Program the alarms via the gold plated jumper tab positions located on the CPU board (see figure 3A). Alarm 1
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 dur-
Figure 3A
Control Circuit - Side View
CPU Board - Top View
Alarm Programming Jumpers
FAULT
ALARM 1
CPU Board
M
AR
AL
As
En cen Latc
er din h
giz g
e
2
Latch
Energize
Latch
Ascending
Energize
ing descending gas conditions.
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, toxic gas 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”
(see figure 3).
f) If applicable, set the RS-485 ID number via the two rotary dip switches located on the preamp board (see figure
3B). There are 256 different ID numbers available which are based on the hexidecimal numbering system. If RS-485
communications are used, each sensor must have its own unique ID number. Use a jewelers screwdriver to set the
rotary dip switches according to the table listed on the following page. If RS-485 communications are not used,
leave the dip switches in the default position which is zero/zero (0)-(0).
PI-600 Toxic Gas Sensors PG.17
g) Replace the plug-in control circuit and replace the junction box cover.
Control Circuit - Side View
Preamp Board - Side View
RS-485 ID Set Dip Switches
3456
BCDE
F012
SW2
7 8 9A
3456
SW1
BCDE
F012
7 8 9A
Figure 3B
Preamp Board
3.4.5 Remote Mounting Applications
Some sensor mounting applications require that the gas sensor head be remotely mounted away from the sensor transmitter. This is usually true in instances where the gas sensor head must be mounted in a location that is difficult to
access. Such a location creates problems for maintenance and calibration activities. Detcon provides the PI-600 sensor
in a remote-mount configuration in which the sensor (Model PI-600-RS) and the transmitter (Model PI-600-RT) are provided in their own condulet housing and are interfaced together with a four conductor cable. Reference figure 4 for
wiring diagram.
Remote Transmitter
PM-600-RT
Remote Sensor
PI-600-RS
WHT
BLK
YEL
BLU
WHT
BLK
YEL
BLU
1234
Figure 4
PI-600 Toxic Gas Sensors PG.18
3.5 START UP
Upon completion of all mechanical mounting and termination of all field wiring, apply system power and observe the
following normal conditions:
a) PI-600 “Fault” LED is off.
b) A temporary upscale reading will occur as the sensor powers up. This upscale reading should clear to “0” ppm within approximately 5-10 minutes of turn-on, assuming there is no gas in the area of the sensor.
NOTE 1: If the display contrast needs adjustment, refer to section 3.11.
NOTE 2: If the sensor does not clear to zero after 15 minutes of warm-up, there may be target VOC gases present in the area.
3.5.1 Initial Operational Tests
After a warm up period has been allowed for, the sensor should be checked to verify sensitivity to its target gas.
Material Requirements
* Detcon PN 943-000006-132 Calibration Adapter
* Span gas containing isobutylene in air. It is recommended that the target gas concentration be 50% of scale at a controlled flow rate of 200 cc/min. For example, a Model PI-600 sensor in the range 0-100ppm would require a test gas of
50ppm isobutylene. For a sensor with a range of 0-10ppm a test gas of 5ppm is recommended, etc. Other concentrations are acceptable as long as they are between 10%-90% of full-scale range.
a) Attach the calibration adapter to the sensor housing. Apply the test gas at a controlled flow rate of 200 cc/min.
Observe that the LCD display increases to a level of ±10% of applied concentration.
b) Remove the test gas and observe that the LCD display decreases to “0 PPM”.
Initial operational tests are complete. Detcon PID gas sensors are pre-calibrated prior to shipment and will, in most
cases, not require significant adjustment on start up. However, it is recommended that complete zero and span calibrations be performed within 24 hours of installation. Refer to calibration instructions in later text.
3.6 OPERATING SOFTWARE & MAGNETIC INTERFACE
Operating software is menu listed with operator interface via the two magnetic program switches located under the face
plate. 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. (Note: see section 3.7 for a complete software flow chart.)
01. Normal Operation
a) Current Status
02. Calibration Mode
a) Zero
b) Span
03. Program Menu
a) View Program Status
b) Alarm 1 Level
c) Alarm 2 Level
d) Set Calibration Level
e) Set Response Factor
f) Set Zero Offset
3.6.1 Normal Operation
In normal operation, the display tracks the current status of the sensor and gas concentration and appears as:
“0 PPM xxx” (the “xxx” is the abbreviated gas type, ie., “0 PPM VOC”. The mA current output corresponds to the
monitoring level of 0-100% of range = 4-20 mA.
PI-600 Toxic Gas Sensors PG.19
3.6.2 Calibration Mode
Calibration mode allows for sensor zero and span adjustments. “1-ZERO 2-SPAN”
3.6.2.1 Zero Adjustment
Zero is set in ambient air with no target gas present or with zero gas applied to the sensor. “AUTO ZERO”
3.6.2.2 Span Adjustment
Span adjustment is performed with a target gas concentration of 50% of range in air. Span gas concentrations other than
50% of range may be used. Refer to section 3.6.3.2 for details. “AUTO SPAN”
3.6.3 Program Mode
The program mode provides a program status menu (View Program Status) to check operational parameters. It also
allows for the adjustment of the calibration gas level setting.
3.6.3.1 Program Status
The program status scrolls through a menu that displays:
* The software version number.
* Range is ###
* The alarm set point level of alarm 1. The menu item appears as: “ALM1 SET @ ##PPM”
* The alarm firing direction of alarm 1. The menu item appears as: “ALM1 ASCENDING” or descending.
* The alarm relay latch mode of alarm 1. The menu item appears as: “ALM1 NONLATCHING” or latching.
* The alarm relay energize state of alarm 1. The menu item appears as: “ALM1 DE-ENERGIZED” or energized.
* The alarm set point level of alarm 2. The menu item appears as: “ALM2 SET @ ##PPM”
* The alarm firing direction of alarm 2. The menu item appears as: “ALM2 ASCENDING” or descending.
* The alarm relay latch mode of alarm 2. The menu item appears as: “ALM2 LATCHING” or nonlatching.
* The alarm relay energize state of alarm 2. The menu item appears as: “ALM2 DE-ENERGIZED” or energized.
* The alarm relay latch mode of the fault alarm. The menu item appears as: “FLT NONLATCHING” or latching.
* The alarm relay energize state of the fault alarm. The menu item appears as: “FLT ENERGIZED” or deenergized.
* The calibration gas level setting. The menu item appears as: “CalLevel @ xxPPM”
* Identification of the RS-485 ID number setting. The menu item appears as: “485 ID SET @ ##”
* The response factor setting. The item appears as: “RespFactor = x.xx”
* The current zero offset value. The menu item appears as: “ZeroOffset = x.x PPM”
* The raw signal from the sensor head. The menu item appears as: “Raw Signal = x.xx V”
* The estimated remaining sensor life. The menu item appears as: “SENSOR LIFE 100%”
3.6.3.2 Alarm 1 Level Adjustment
The alarm 1 level is adjustable from 10% to 90% of range. The menu item appears as: “SET ALM1 @ ##PPM”
3.6.3.3 Alarm 2 Level Adjustment
The alarm 2 level is adjustable from 10% to 90% of range. The menu item appears as: “SET ALM2 @ ##PPM”
3.6.3.3 Calibration Level Adjustment
The calibration level is adjustable from 10% to 90% of range. The menu item appears as: “CalLevel @ ##PPM”
3.6.3.4 Response Factor Adjustment
The Response Factor is set according to the primary target gas being detected. The menu item appears as:
“RespFactor = x.xx”
3.6.3.5 Zero Offset
The Zero Offset is settable between 0 and 10 ppm to account for residual backgrounds of active VOCs in ambient air. The
menu item appears as: “ZeroOffset = x.x PPM”
3.6.3.6 Raw Signal
The raw signal from the sensor head is displayed for the purpose of troubleshooting.
PI-600 Toxic Gas Sensors PG.20
3.6.4 Programming Magnet Operating Instructions
Operator interface to MicroSafe™ gas detection products is via magnetic switches located behind the transmitter face
plate. 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 programming without removing the enclosure cover, thereby eliminating the need for area de-classification or the use of hot permits.
A magnetic programming tool (see figure 5) is used to operate the switches. Switch action is defined as momentary con-
Magnetic Programming Tool
Figure 5
tact, 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
thirty 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 figure 6.
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.
Program Switch #1
Plug-in Universal Microprocessor
Control Circuit
CONTRAST
PGM
Display Contrast Adjust
MODEL
0
Figure 6
1
detcon inc.
HOUSTON, TEXAS
PI-600
PPM VOC
Menu Driven Display
MicroSafe™ Gas Sensor
FLT
ALM ALM
1
2 CAL
PGM
Program Switch #2
2
UNIVERSAL
TRANSMITTER
PI-600 Toxic Gas Sensors PG.21
Alarm & Cal LEDs
3.7 SOFTWARE FLOW CHART
AUTO ZERO
LEGEND
PGM1 - program switch location #1
PGM2 - program switch location #2
(M) - momentary pass of magnet
(3) - 3 second hold of magnet
(30) - 30 second hold of magnet
INC - increase
DEC - decrease
# - numeric value
AUTO SPAN
PGM1 (3) PGM2 (3)
CALIBRATION
1-ZERO 2-SPAN
PGM1 (3)
NORMAL
OPERATION
PGM2 (30)
VIEW PROG STATUS
SET ALARM 1 LEVEL
SET ALARM 2 LEVEL
SET CAL LEVEL
SET RESPONSE FACTOR
SET ZERO OFFSET
PGM1 (3) PGM2 (M)
PGM1 (3) PGM2 (M)
PGM1 (3) PGM2 (M)
PGM1 (3) PGM2 (M)
PGM1 (3) PGM2 (M)
PGM1 (3) PGM2 (M)
PGM2 (3)
PGM2 (3)
PGM2 (3)
PGM2 (3)
PGM2 (3)
PGM2 (3)
SET ALM1 @ ##PPM
Software Version V#.#
INC
GAS RANGE
PGM1 (M) PGM2 (M)
PGM1 (3)
CalLevel @ ##PPM
SET ALM2 @ ##PPM
DEC
INC
PGM1 (M) PGM2 (M)
PGM1 (3)
DEC
INC
PGM1 (M) PGM2 (M)
PGM1 (3)
RESPFACTOR = X.XX
DEC
INC
PGM1 (M) PGM2 (M)
PGM1 (3)
ZERO OFFSET = X.X PPM
DEC
INC
PGM1 (M) PGM2 (M)
DEC
PGM1 (3)
ALM1 SET @ ##PPM
ALM1 (Firing Direction)
ALM1 (Latch State)
ALM1 (Energize State)
Figure 7
ALM2 SET @ ##PPM
ALM2 (Firing Direction)
ALM2 (Latch State)
ALM2 (Energize State)
FLT (Latch State)
FLT (Energize State)
CAL LEVEL @ ##PPM
485 ID SET @ #
ZERO OFFSET = X.XX
RAW SIGNAL = X.XX V
SENSOR LIFE ##%
3.8 CALIBRATION
Material Requirements
* Detcon PN 943-003270-000 MicroSafe™ Programming Magnet
* Detcon PN 943-000006-132 Calibration Adapter
* Zero Air gas containing no VOC compounds
* Span gas containing isobutylene in air. The cal gas concentration is recommended at 50% of range (which is the factory default) at a controlled flow rate of 200 cc/min. Example: for a Model PI-600 sensor with a range of 0-100ppm,
a test gas of 50 ppm isobutylene is recommended. For a sensor with a range of 0-10 ppm a test gas of 5 ppm is recommended, etc. Other concentrations can be used as long as they fall within 10% to 90% of range. See section
3.8.2 for details. Reference section 3.9-b-1 if you do not know the sensor target gas or range of detection.
3.8.1 Calibration Procedure - Zero
NOTE 1: Before performing a zero calibration, determine if there are any active VOC target gases in the area. If it can
be concluded that there are no active VOC gases in the area, then execute steps b) and c) below.
PI-600 Toxic Gas Sensors PG.22
NOTE 2: Assuming that there are some residual VOC target gases in the background, you will require the use of the
zero air gas standard to perform a correct zero calibration starting from step a) below.
a) Apply a zero air standard at 200 cc/min for approximately 2-3 minutes then proceed through steps b) and c) with the
gas under continuous flow. After applying gas, tap your fingertip over the exit port of the cal adapter for 10 -30
seconds to expedite the gas purging process.
b) Enter the calibration menu by holding the programming magnet over PGM 1 (see Figure #6) for 3 seconds until the
display reads “1-ZERO 2-SPAN”, then withdraw the magnet. Note that the Cal LED should now be illuminated.
c) Next, enter the zero menu by holding the magnet stationary over “PGM 1” for 3 seconds until the display reads:
“Setting Zero”, then withdraw the magnet. The sensor has now entered the auto zero mode. When it is complete
the display will read “ZERO COMPLETE” for 5 seconds and then return to the normal operations menu reading.
d) Remove the zero air gas and cal adapter and allow the sensor 3-5 minutes to rest on ambient air. If there are residual
active VOC gases in the area, then the sensor will read higher than 0.0 ppm. If this is the case, then you can use
the Zero Offset feature to correct for this residual background amount.
e) Set the Zero Offset value according to the concentration value found following the zero calibration procedure. See
section 3.8.1.1 below.
3.8.1.1 Using the Zero Offset Feature
If it is determined that there is a constant and non-negligible amount of residual active VOC gases in the background
air, the Zero Offset feature can be used to correct for this.
a) Observe the sensor’s concentration reading on air after a zero air calibration procedure. This represents the background VOC contribution that you will be offsetting.
b) Access the Zero Offset software feature by applying the magnet to PGM2 for 15 seconds. Then use the magnet to
momentarily pass over PGM1 and advance to the “Set Zero Offset” menu. Then apply the magnet to PGM1 for 3
seconds to access this menu. The menu should now read as “Zero Offset = X.X. Use PGM1 to increment this
number up to your desired offset level. When the correct offset is set, apply the magnet to PGM1 for 3 seconds to
accept the value. Then apply the magnet to PGM2 for 3 seconds to return to Normal Operation.
c) When done correctly, the unit should read 0.0 when back in Normal Operation.
3.8.2 Calibration Procedure - Span
3.8.2.1 Set Response Factor
All span calibrations are recommended to be done with a calibration standard consisting of isobutylene in an air background. If your target gas is different than the isobutylene span gas, you will be required to apply the correct Response
Factor. Look up the Response Factor for your target gas in the Table shown in Section 3.2.3.
a) Enter the programming menu by holding the magnet stationary over “PGM2” for 15 seconds until the display reads
“View Program Status”, then withdraw the magnet. At this point you can scroll through the programming menu by
momentarily waving the magnet over “PGM1” or “PGM2”. The menu options are: View Program Status, Set Cal Level,
Set Response Factor, and Set Zero Offset. Scroll to the “Set Response Factor” selection.
b) Select “Set Response Factor” by holding the magnet over “PGM1” for 3 seconds until the display reads “RespFactor
= x.xx”, then withdraw the magnet. Use the magnet to make an adjustment to “PGM1” to increase or “PGM2” to
decrease the displayed value until the value is equal to the desired “Response Factor” value from Section 3.2.3.
NOTE: If you have multiple target gases, then select the target gas with the highest Response Factor from the Table.
This provides for the safest and earliest warning levels.
NOTE: If you are span calibrating with the target gas, instead of isobutylene, then the response factor should be left at 1.0
3.8.2.2 Span Calibration
NOTE: Isobutylene is the recommended calibration gas for this sensor.
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.
PI-600 Toxic Gas Sensors PG.23
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. This concentration must be equal to the calibration gas level setting. The factory default setting for span gas concentration is 50% of range. In this instance, a span gas
containing a concentration equal to 50% of range is required. If a span gas containing 50% of range is not available,
other concentrations may be used as long as they fall within 10% to 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.
a) Verify the current calibration gas level setting as indicated by the programming status menu. To do this, follow the
instructions in section 3.9 and make note of the setting found in listing number 2. The item appears as
“GasLevel @ xxPPM”.
b) If the calibration gas level setting is equal to your calibration span gas concentration, proceed to item “f”. If not,
adjust the calibration gas level setting so that it is equal to your calibration span gas concentration, as instructed in
items “c” through “e”.
c) Enter the programming menu by holding the programming magnet stationary over “PGM 2” for 15 seconds until
the display reads “VIEW PROG STATUS”, then withdraw the magnet. At this point you can 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 Cal Level, Set Response Factor, and Set Zero Offset.
d) 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 “CalGas @ ##PPM”, then withdraw the magnet. Use the programming magnet to make an adjustment to “PGM 1” to increase or “PGM 2” to decrease the display reading until the reading is equal to the desired
calibration span gas concentration. Exit the programming menu by holding the programming magnet over “PGM1”
for 3 seconds.
e) Exit back to normal operation by holding the programming magnet over “PGM 2” for 3 seconds, or automatically
return to normal operation in 30 seconds.
f) From the calibration menu “1-ZERO 2-SPAN” proceed into the span adjust function by holding the programming magnet stationary over “PGM 2” for 3 seconds then withdraw the programming magnet. At this point the
display will ask for the application of the target gas and concentration. The display reads “APPLY xxPPM ISO”
The x’s here will indicate the actual concentration requested.
g) Apply the calibration test gas at a flow rate of 200 cc/min. After applying the span gas, hold your fingertip (blocking) over the exit port of the cal adapter for 10-30 seconds. This helps to expedite the purging of the internal sensor chamber. As the sensor signal changes, the display will change to “AutoSpan xxPPM”. The “xx” part of the
reading indicates the actual gas reading which will increase until the sensor stabilizes. When the sensor signal is stable it will auto span to the correct ppm reading and the display will change to “SPAN COMPLETE” for 3 seconds, then to “SENSOR LIFE: xxx%”and then “REMOVE GAS”. Remove the gas. When the signal level has
fallen below 10% of full scale, the display will return to the normal operating mode.
NOTE 1: If there is not a minimal response to the cal gas in the first minute, 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 screen which appears as: “SPAN FAULT #1” (see section 3.8.3).
NOTE 2: If during the auto-span function the sensor fails to meet a minimum signal stability criteria, the sensor
will enter the calibration fault mode which will cause the display to alternate between the sensor’s current status
reading and the calibration fault screen which appears as: “SPAN FAULT #2” (see section 3.8.3).
3.8.3 Additional Notes
1. Upon entering the calibration menu, the 4-20 mA signal drops to 2 mA and is held at this level until you return to
normal operation.
2. 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 which will activate the fault LED (see section 3.10) and will cause the display to
alternate between the sensor’s current status reading and the calibration fault description. In these cases, the previous
calibration points will remain in memory. If this occurs you may attempt to recalibrate by entering the calibration
menu as described in section 3.8.1-a. If the sensor fails again, defer to technical trouble shooting (see section 3.13).
PI-600 Toxic Gas Sensors PG.24
3.8.4 Calibration Frequency
In most applications, monthly to quarterly calibration intervals will assure reliable detection. However, industrial environments differ. Upon initial installation and commissioning, close frequency tests should be performed, weekly to
monthly. Test results should be recorded and reviewed to determine a suitable calibration interval.
3.8.5 PID Plug-In Sensor Maintenance
The plug-in PID Sensor will need to be properly maintained to achieve proper long-term performance. All PID sensors
use a UV lamp that has a finite lifetime. The Detcon PID UV lamp source is expected to last a least 1 year. However,
from the time of installation a gradual loss in UV lamp strength is expected. (See Figure 8) As the UV lamp strength
decreases the sensor signal will decrease accordingly. This dictates that periodic span calibrations are required to maintain calibration accuracy.
Figure 8
To determine the present signal strength of the PID sensor, execute a valid span calibration and view the Sensor Life
from the ‘View Program Status’ menu. Any Sensor Life value less than 30% should result in the user’s choice of replacing the plug-in sensor, cleaning the UV Lamp, or replacing the UV Lamp.
If the PID sensor seems to be losing signal strength at a rate faster than Figure 8 estimates, the sensor is most likely
experiencing contamination film build-up on the UV optical filter. This will happen when exposed to certain gases or
ambient contaminations that collect on the surafce of the UV filter. The result is a decrease in the amount of emitted
UV from the lamp source. This is known to happen with gases that can be polymerized by UV light (such as heavy
complex VOC’s), airborne oil vapors, and very fine dust. As UV Filter contamination occurs, the sensor’s signal
strength falls off in addition to the expected loss rate shown in Figure 8. This phenomenon can be reversed by disassembling the sensor and carefully cleaning the UV lamp filter using a specialized cloth.
It is also possible under certain ambient contamination conditions that the sensor’s Detector Cell can have a partially
conductive film that forms across the contact grids. This condition causes the zero background signal to gradually
increase to the point where it becomes unacceptable for the range of signal input to the transmiter electronics. When
this occurs the detector cell should be replaced. This can be checked by examining the amount of raw signal that is
produced during exposure to zero gas. Refer to the ‘View Program Status’ menu and record the Raw Signal report after
5 minutes of zero gas exposure. A value that exceds 2.65V would be evidence of this problem.
3.8.5.1 General recomendations for Sensor Maintenance
1) For normal environmental exposure and signal decay, replace the plug-in sensor every 9-12 months (especially if
there are no skilled technicians to handle proper UV lamp replacement).
PI-600 Toxic Gas Sensors PG.25
2) If skilled technicians are available, replace just the UV lamp every 9-12 months.
3) For abnormally high rates of signal decay, clean the UV lamp monthly, using a Lamp Cleaning Kit, and replace the
UV lamp every 9-12 months.
4) For any proven cases where the zero baseline has drifted up, replace the detector cell.
3.8.5.2 PID Plug-In Sensor Maintenance Procedure
All piD Sensor Cells contain six user replacable parts.
Disassembly
1) Power down the instrument and remove the sensor cell.
2) Remove the filtercap by applying a slight upward pressure with the tip of a screwdriver or an Exacto Blade just
below the hole in the cap and between the cap and the housing.
3) With a fine tipped tweezers, remove both of the Filter Media and set aside.
PI-600 Toxic Gas Sensors PG.26
4) Using an Exacto Blade, remove the spacer and set it aside
5) With fine tipped tweezers, carfully remove the cell assembly by prying under the cell’s edge where the connector
pins are located.
6) With fine tipped tweezers, grasp the lamp by placing the tips in the housing notch and gently pull it out. Be careful
not to scratch the lamp lens or chip the edges.
Cleaning the Lamp
PI-600 Toxic Gas Sensors PG.27
Grab the lamp by the cylindrical glass body and clean the window by rubbing it against the polishing pad. Use a circular motion and try to keep the window surface flat relative to the pad. Five seconds of rubbing should be enough in
most cases. Another indication of cleaning completeness is that about 1/16th of the pads surface is used in the process.
Reassembly
1) Install the lamp into the sensor, making sure that the lamps metalized pads are aligned with the corresponding excitation springs inside the lamp cavity.
2) With the end of the clean tweezers, or a clean blade of a screwdriver, press down firmly, being careful not to scratch
the surface of the lamp.
3) Using fine tipped tweezers, install the cell assembly. Align the pins with the corresponding sockets on the sensor
PI-600 Toxic Gas Sensors PG.28
and push down on the end with the pins. Make sure the cell assembly is flush with the lamp window.
4) Place the spacer around the assembly.
5) Place the filter media over the Cell Assembly centered on the top of the sensor. Make sure the filters are installed in
the correct order. Filter Media #2 first, then Filter Media #1 on top, with the shiny side up.
6) Align the Cap Key with the notch on the housing. Starting at the side opposite the notch, press down until the
Filter Cap snaps on to the housing. If the Cap Key is incorrectly aligned there will be a noticable buldge on the side of
the Cap.
PI-600 Toxic Gas Sensors PG.29
3.9 STATUS OF PROGRAMMING, CALIBRATION LEVEL, AND SENSOR LIFE
The programming menu has a “View Program Status” listing that allows the operator to view the gas, range, and software version number of the program, as well as current alarm settings, the calibration gas level setting, RS-485 ID, and
estimated remaining sensor life. The programming menu also allows the changing of alarm levels (see section 3.10) and
the calibration gas level setting (see section 3.8.2.2).
The following procedure is used to view the programming status of the sensor:
a) First, enter the programming menu by holding the programming magnet stationary over “PGM 2” for 30 seconds
until the display reads “VIEW PROG STATUS”, then withdraw the magnet. At this point you can scroll
through the programming menu by momentarily waving the programming magnet over “PGM 1” or “PGM 2”. The
menu options are: View Program Status, and Set Cal Level.
b) Next, scroll to the “VIEW PROG STATUS” listing and then hold the programming magnet over “PGM 1” for 3
seconds. The menu will then automatically scroll, at five second intervals, through the following information before
returning back to the “VIEW PROG STATUS” listing.
1 - The software version number.
2 - Range is ###.
3 - The alarm set point level of alarm 1. The menu item appears as: “ALM1 SET @ xxPPM”
4 - The alarm firing direction of alarm 1. The menu item appears as: “ALM1 ASCENDING”
5 - The alarm relay latch mode of alarm 1. The menu item appears as: “ALM1 NONLATCHING”
6 - The alarm relay energize state of alarm 1. The menu item appears as: “ALM1 DE-ENERGIZED”
7 - The alarm set point level of alarm 2. The menu item appears as: “ALM2 SET @ xxPPM”
8 - The alarm firing direction of alarm 2. The menu item appears as: “ALM2 ASCENDING”
9 - The alarm relay latch mode of alarm 2. The menu item appears as: “ALM2 LATCHING”
10 - The alarm relay energize state of alarm 2. The menu item appears as: “ALM2 DE-ENERGIZED”
11 - The alarm relay latch mode of the fault alarm. The menu item appears as: “FLT NONLATCHING”
12 - The alarm relay energize state of the fault alarm. The menu item appears as: “FLT ENERGIZED”
13 - Calibration gas level setting. The menu item appears as: “CalLevel @ xxPPM”
14 - Identification of the RS-485 ID number setting. The menu item appears as: “485 ID SET @ 1”
15 - Response Factor Setting. The menu item appears as: “RespFactor = x.xx”
16 - Zero Offset Setting. The menu item appears as: “ZeroOffset = x.x”
17 - Raw signal from sensor head. The menu item appears as: “RawSignal = x.xxV”
18 - The estimated remaining sensor life. The menu item appears as: “SENSOR LIFE 100%”
c) Exit back to normal operations by holding the programming magnet over “PGM 2” for 3 seconds, or automatically
return to normal operation in 30 seconds.
3.10 PROGRAMMING ALARMS
3.10.1 Alarm Levels
Both alarm 1 and alarm 2 levels are factory set prior to shipment. Alarm 1 is set at 20% of range and alarm 2 at 40% of
range. Both alarms can be set in 1% increments from 10% to 90% of range. The following procedure is used to change
alarm set points:
PI-600 Toxic Gas Sensors PG.30
a) First, enter the programming menu by holding the programming magnet stationary over “PGM 2” for 30 seconds
until the display reads “VIEW PROG STATUS”, then withdraw the magnet. At this point you can 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 From the programming menu scroll to the alarm 1 level listing. The menu item 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”, then withdraw the magnet. Use the programming magnet to make an adjustment to “PGM 1” to increase or “PGM 2” to decrease the display reading until the reading is
equal to the desired alarm set point. Exit to the programming menu by holding the programming magnet over
“PGM1” for 3 seconds, or automatically return to the programming menu in 30 seconds.
c) ALARM 2 LEVEL From the programming menu scroll to the alarm 2 level listing. The menu item 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”, then withdraw the magnet. Use the programming magnet to make an adjustment to “PGM 1” to increase or “PGM 2” to decrease the display reading until the reading is
equal to the desired alarm set point. Exit to the programming menu by holding the programming magnet over
“PGM1” for 3 seconds, or automatically return to the programming menu in 30 seconds.
d) Exit back to normal operations by holding the programming magnet over “PGM 2” for 3 seconds, or automatically
return to normal operation in 30 seconds.
3.10.2 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.
3.10.3 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. See section 3.4.4 for details.
3.11 PROGRAM FEATURES
Detcon MicroSafe™ PID gas sensors incorporate a comprehensive program to accommodate easy operator 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 range, it will cause the display to flash the highest reading of its range on
and off.
Under Range Fault(s)
If the sensor should drift below a zero baseline of -10% of range, the display will indicate a fault: “ZERO FAULT”.
This is typically fixed by performing another zero cal. When the total negative zero drift exceeds the acceptable threshold the display will indicate “SENSOR FAULT” and you will longer be able to zero calibrate.
Span Fault #1
If during span calibration the sensor circuitry is unable to attain a minimum defined response to span gas, 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: “SPAN FAULT #1”. The previous calibration settings will remain saved in
memory. Previous span calibration is retained.
Span Fault #2
If during the span routine, the sensor circuitry is unable to attain a minimum defined stabilization point, the sensor will
enter into the calibration fault mode and cause the display to alternate between the sensor’s current status reading and the
PI-600 Toxic Gas Sensors PG.31
calibration fault screen which appears as “SPAN FAULT #2”. Previous span calibration is retained.
Memory Fault
If new data points cannot successfully be stored to memory the display will indicate: “MEMORY FAULT”.
Fail-Safe/Fault Supervision
Detcon MicroSafe™ sensors are programmed for fail-safe operation. All fault conditions will illuminate the fault LED,
and cause the display to read its corresponding fault condition: “ZERO FAULT”, “SENSOR FAULT”, “SPAN
FAULT #1”, or “SPAN FAULT #2”. A “SENSOR FAULT” and “ZERO FAULT” will cause the mA output to
drop to zero (0) mA.
Sensor Life
The “Sensor Life” feature gauges the remaining sensor life based on signal output from the PID sensor cell. When a sensor life of 25% or less remains, the sensor cell should be replaced within a reasonable maintenance schedule.
3.12 DISPLAY CONTRAST ADJUST
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 jewelers screwdriver to turn the contrast adjust screw
located beneath the metallic face plate. The adjustment location is marked “CONTRAST”. See figure 6 for location.
3.13 UNIVERSAL TRANSMITTER FEATURE (RE-INITIALIZATION)
The Model PI-600 uses a universal transmitter design that allows the transmitter to be set up for any target gas and any
toxic concentration range. The original transmitter set-up is done at Detcon Inc. as part of the sensor test and calibration procedure, but it may also be changed in the field if necessary. The Universal Transmitter feature is a significant
convenience to the user because it allows hardware flexibility and minimizes the spare parts requirements to handle
unexpected transmitter failures of different gas/ranges. It is however, absolutely critical that changes to gas/range set-up
of the Universal Transmitter be consistent with the gas type and range of the PID Sensor Head that it is connected to.
The PID sensor head will display the range it is set up for, based on the isobutylene reference calibration.
NOTE: If the Universal Transmitter is changed for gas type and range, it must be consistent with the PID sensor head
it is mated with.
If the Universal Transmitter needs to be changed for gas type and range follow this procedure. First, unplug the transmitter temporarily and then plug it back in. While the message “Universal Transmitter” appears, take the program magnet and swipe it over magnet PGM1. This will reveal the set-up options for gas range and gas type.
Swipe over PGM1to advance through the options for gas range which include:
1, 2, 3….10 ppm
10, 15, 20……100 ppm
100, 200, 300…..1000 ppm
1000, 2000, 3000 …..10,000 ppm
When the correct range is displayed, hold magnet over PGM1 for 3 seconds to accept the selection.
Next is your selection for the gas type that will be displayed. Note, the default gas is “VOC”. In this set-up you will
enter the alpha-numeric characters of the gas type. There is space for the chemical formula name of up to six characters.
Use PGM1 and PGM2 swipes to advance through the alphabet and numbers 0-9 selection (there is a blank space after
9). When the correct alphanumeric character is highlighted, hold the magnet over PGM1 for 3 seconds to lock it in.
This moves you to the next blank and the procedure is repeated until the chemical formula is completed. After the 6th
character is locked in the transmitter will proceed to normal operation.
PI-600 Toxic Gas Sensors PG.32
NOTE 1: If the gas symbol has more than 6 characters, the symbol can be replaced by an abbreviated version of the
target gas name such as TOL or TOLUEN for Toluene which has a the symbol C6H5CH3. For epichlorohydrin (symbol C3H5OCL) you can substitute the name EPI or EPICHL etc.
NOTE 2: When the Universal Transmitter is re-initialized and a new gas and range is entered, the previous customer
settings for span gas value, response factor, and zero offset are reset to default levels. This must be re-programmed back
to the customer specific settings.
3.14 RS-485 PROTOCOL
Detcon MicroSafe™ toxic gas 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 3.2.5.4-f for details on changing the RS-485 ID number.
The following section explains the details of the Modbus™ protocol that the MicroSafe™ sensor supports.
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 #
40000
High Byte
Gas type
Low Byte
Sensor Life
Gas type is one of the following:
01=CO, 02=H2S, 03=SO2, 04=H2, 05=HCN, 06=CL2, 07=NO2, 08=NO, 09=HCL, 10=NH3, 11=LEL, 12=O2
Sensor life is an estimated remaining use of the sensor head, between 0% and 100%
Example: 85=85% sensor life
Register #
40001
High Byte
Low Byte
Detectable Range
i.e. 100 for 0-100 ppm, 50 for 0-50 ppm, etc.
Register #
40002
High Byte
Low Byte
Current Gas Reading
The current gas reading as a whole number. If the reading is displayed as 23.5 on the display, this register would contain
the number 235.
Register #
40003
High Byte
Low Byte
Alarm 1 Set point
This is the trip point for the first alarm.
Register #
High Byte
Low Byte
PI-600 Toxic Gas Sensors PG.33
40004
Alarm 2 Set point
This is the trip point for the second alarm.
Register #
40005
High Byte
Status Bits
Low Byte
Status Bits
High Byte
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Not used, always 0
Not used, always 0
Not used, always 0
Not used, always 0
1-Unit is in calibration
1-Alarm 2 is ascending
1-Alarm 2 is normally energized
1-Alarm 2 is latching
0-Normal operation
0-Alarm 2 is descending
0-Alarm 2 is normally de-energized
0-Alarm 2 is non-latching
Low Byte
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
1-Alarm 2 Relay is energized
1-Alarm 1 is ascending
1-Alarm 1 is normally energized
1-Alarm 1 is latching
1-Alarm 1 Relay is energized
1-Fault is normally energized
1-Fault is latching
1-Fault Relay is energized
0-Alarm 2 Relay is not energized
0-Alarm 1 is descending
0-Alarm 1 is normally de-energized
0-Alarm 1 is non-latching
0-Alarm 1 Relay is not energized
0-Fault is normally de-energized
0-Fault is non-latching
0-Fault Relay is not energized
The following is a typical Master Query for device # 8:
Field Name
Slave Address
Function
Start Address Hi
Start Address Lo
No. of Registers Hi
No. of Registers Lo
CRC
CRC
HEX
08
03
00
00
00
06
##
##
DEC
8
3
0
0
0
6
RTU
0000 1000
0000 0011
0000 0000
0000 0000
0000 0000
0000 0110
#### ####
#### ####
The following is a typical Slave Response from device # 8:
Field Name
Slave Address
Function
Byte Count
Reg40000 Data Hi
Reg40000 Data Lo
Reg40001 Data Hi
Reg40001 Data Lo
Reg40002 Data Hi
Reg40002 Data Lo
Reg40003 Data Hi
Reg40003 Data Lo
HEX
08
03
0C
02
64
00
64
00
07
00
0A
DEC
8
3
12
2
100
0
100
0
7
0
10
RTU
0000 1000
0000 0011
0000 1100
0000 0010
0110 0100
0000 0000
0110 0100
0000 0000
0000 0111
0000 0000
0000 1010
PI-600 Toxic Gas Sensors PG.34
Reg40004 Data Hi
Reg40004 Data Lo
Reg40005 Data Hi
Reg40005 Data Lo
CRC
CRC
00
14
05
50
##
##
0
20
5
80
0000 0000
0001 0100
0000 0101
0101 0000
#### ####
#### ####
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, half duplex 485.
On ranges set from 1 ppm to 10 ppm the reading and alarm set points are displayed as ##.##ppm.
On ranges set from 15 ppm to 50 ppm the reading and alarm set points are displayed as ##.#ppm.
To accommodate these fractional readings using the Modbus™ interface, the reading and alarm set points are multiplied by 100 before they are stored for retrieval by a Modbus™ command.
Examples:
The transmitter is set for a range of 5 ppm.
The display on the transmitter reads 2.74 ppm.
The transmitter is polled for its reading using a Modbus™ command.
The value returned in the response is decimal 274.
Obtain the correct reading by dividing.
274/100 = 2.74 ppm.
The transmitter is set for a range of 25 ppm.
The display on the transmitter reads 22.9 ppm.
The transmitter is polled for its reading using a Modbus™ command.
The value returned in the response is decimal 2290.
Obtain the correct reading by dividing.
2290/100 = 22.9 ppm.
On ranges above 50 ppm there is no math involved. The readings are stored the same as they are seen on the transmitters display.
3.15 TROUBLE SHOOTING
Sensor reads Over-range after Power-up
Probable Cause: Sensor requiring additional stabilization time, VOC gases present in background air, Improper zero or
span calibration.
1. Verify that there is not large amounts of target gas or interfering gases in background.
2. Redo zero and span calibrations.
3. Make sure transmitter range is consistent with PID sensor head range.
Reading Higher than Anticipated
Probable Causes: Target or Interfering gases in background, Incorrect calibration for Zero or Span.
1. Verify no target or interfering gases are present. If so, use the Zero Offset feature.
2. Redo Zero and Span calibrations with validated Zero Gas and Span Gas standards.
Reading Lower than Anticipated
Probable Causes: Zero Calibration done before unit finished stabilizing, Incorrect Span Calibration.
1. Redo Zero and Span calibrations with validated Zero Gas and Span Gas standards.
2. Disengage Zero Offset feature if it is not necessary.
3. Contact Detcon to determine if target gas will not diffuse past the 316 Stainless Steel flame arrestor.
Zero Calibration Fault
Probable Causes: Target gas or Interfering gases in background during Zero Calibration, Failed PID sensor.
PI-600 Toxic Gas Sensors PG.35
1. Verify no target or interfering gases are present.
2. Redo Zero calibration with validated Zero Gas standard.
3. If recovering after a start-up, give more time to stabilize.
Span Calibration Fault
Probable Causes: Failed PID sensor (failed UV lamp bulb, optical window needs cleaning), ice/mud/dust blocking protective membrane, invalid span calibration gas due to age, type, and contamination or insufficient flow rate.
1. Verify there is no ice/mud/dust blocking the sensor’sFlame Arrestor.
2. Redo Span Calibration with validated Isobutylene Span Gas standard.
3. Reinitialize unit by plugging in transmitter while holding the magnet on PGM1. Scroll through and select the correct gas type. Make sure all customer settings are re-entered after “reinitialization”.
4. Clean UV Lamp Filter or replace UV Lamp.
5. Replace with new PID sensor.
Noisy Sensor (continuous drift) or suddenly Spiking
Probable Cause: Unstable power source, Inadequate grounding, Inadequate RFI protection.
1. Verify power Source output and stability.
2. Contact Detcon for assistance in optimizing shielding and grounding.
3. Add RFI Protection accessory available from Detcon.
LCD Difficult to Read
Probable Cause: Needs adjustment.
1. Adjust contrast pot as necessary.
Reporting “ERROR @ XXXXXXX”
Probable Cause: Span calibration calculation error.
1. Reinitialize unit by plugging in transmitter and the swiping the magnet over PGM1 while “Universal Transmitter” is
displayed. Scroll through and select the correct gas type and range (see section 3.12 Universal Transmitter Features).
Make sure all customer specific settings are re-entered after “reinitialization”.
3.16 SPARE PARTS LIST
943-000006-132
500-001794-004
327-000000-000
897-850800-000
897-850700-000
960-202200-000
926-P16480-range
370-P10000-000
370-P20000-000
975-600020-000
975-600100-000
975-520040-000
390-404142-range*
Calibration Adapter
Connector board
Programming Magnet
3 port enclosure less cover
Enclosure glass lens cover
Condensation prevention packet (replace annually).
PI-600 Series Universal Plug-in Control Circuit
Plug-in Replaceable PID sensor for 0-20 ppm and lower ranges (PI-600 Model)
Plug-in Replaceable PID sensor for =>50 ppm ranges (PI-601 Model)
PID 10.6eV Replacement Lamp
PID Detector Replacement Cell
PID Lamp Cleaning Kit
PID sensor head assembly
* Does not include plug-in replacement sensor cell.
Specify 3 Digit Range for PID sensor head as per examples below: If greater than 999ppm, use a “K” (for 1000). If
greater than 9,900ppm use a “P” (for %).
005 = 5 ppm
010 = 10 ppm
020 = 20 ppm
025 = 25 ppm
PI-600 Toxic Gas Sensors PG.36
050 = 50 ppm
100 = 100 ppm
250 = 250 ppm
500 = 500 ppm
01K = 1,000 ppm
05K = 5,000 ppm
Programming Magnet
Enclosure glass lens cover
Plug-in control circuit
Connector Board
Enclosure less cover
PID Sensor Head
Condensation
Prevention Packet
(replace annually)
Plug-in PID Sensor Cell
3.17 WARRANTY
Detcon, Inc., as manufacturer, warrants each new PID plug-in sensor cell, for a specified period under the conditions
described as follows: The warranty period begins on the date of shipment to the original purchaser and ends 12 months
thereafter. The sensor cell is warranted to be 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., 3200 A-1 Research Forest Dr., The Woodlands, Texas 77381, for necessary repairs or replacement.
NOTE: The warranty does not cover conditions where the detector cell or lamp may be dirty and can be restored by
cleaning,
3.18 SERVICE POLICY
Detcon, Inc., as manufacturer, warrants under intended normal use each new PI-600 series plug-in signal transmitter
Control Circuit and PID Sensor Head 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 signal Transmitter shall be repaired or replaced as is deemed necessary by Detcon, Inc., for a
fixed fee of $65.00. Any failed PID Sensor Head circuit shall be repaired or replaced as is deemed necessary by Detcon,
Inc., for a fixed fee of $75.00. 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.
Shipping Address: 3200 A-1 Research Forest Dr., The Woodlands, Texas 7381
Mailing Address: P.O. Box 8067, The Woodlands, Texas 77387-8067
phone 888-367-4286, 713-559-9200 • fax 281-292-2860 • www.detcon.com • sales@detcon.com
PI-600 Toxic Gas Sensors PG.37
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