Chemitec S423/C/OPT User manual

S423/C/OPT
SONDA OSSIGENO OTTICA
OPTICAL OXYGEN PROBE
MANUALE TECNICO / TECHNICAL MANUAL
P/N: ………………….
Rev. 0 Ver. 1.0
EDIZIONE Febbraio 2014 / EDITION February 2014

S
S4 42 23 3/ /C C/ /O OP PT T O Op pt ti ic ca al l
O
Ox xy yg ge en n P Pr ro ob be e
D
Da at ta a S Sh he ee et t
S423/C/OPT Optical oxygen p obe – Data Sheet 9
The S423/C/OPT probe is used for the optical measure of oxygen in pure
and process waters. The principle of measurement is based on the effect of
dynamic luminescence quenching by molecular oxygen.
Applications
• Measure of oxygen in wastewater
• Measure of oxygen in primary, industrial, recirculating water
Features and benefits
• Reliable concentration measurement
using optical measuring process
• Dynamic luminescence measuring method
• AISI 316 or Black rigid PVC sensor body
• Interchangeable cap for luminophore’s replacement
• No mechanically moving parts
• Immediate installation and easy manteinance
• Ability to set salinity and barometric pressure for the compensation of the
oxygen value
Operating principle
A relation exists between the oxygen concentration in the sample and the
luminescence intensity as well as the luminescence lifetime which is
described in the Stern-Volmer-equation (1). Here, τ
0
and τare the
luminescence decay times in absence and presence of oxygen (I
0
and I are
the respective luminescence intensities), [O
2
] the oxygen concentration and
KSV the overall quenching constant.
The collision between the luminophore in its excited state and the quencher
(oxygen) results in radiationless deactivation and is called collisional or
dynamic quenching. After collision, energy transfer takes place from the
excited indicator molecule to oxygen which consequently is transferred from
its ground state (triplet state) to its excited singlet state. As a result, the
indicator molecule does not emit luminescence and the measurable
luminescence signal decreases.

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S4 42 23 3/ /C C/ /O OP PT T O Op pt ti ic ca al l
O
Ox xy yg ge en n P Pr ro ob be e
D
Da at ta a S Sh he ee et t
S423/C/OPT Optical oxygen p obe – Data Sheet 10
Principle of dynamic luminescence method:
Where:
I: Luminescence intensity in presence of oxygen
I
0
: Luminescence intensity in absence of oxygen
τ: Luminescence decay time in presence of oxygen
τ
0
: Luminescence decay time in absence of oxygen
KSV: Stern-Volmer constant (quantifies the quenching efficiency and
therefore the sensitivity of the sensor)
[O
2
]: Oxygen content
(2) Deactivation of the luminescent indicator molecule by molecular oxygen
I
0
/I = T
0
/T= 1+Ksv*O
2
I=f(O
2
) T=f(O
2
)
Principle of dynamic quenching of luminescence by molecular oxygen
(1) Luminescence process in absence of oxygen

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S4 42 23 3/ /C C/ /O OP PT T O Op pt ti ic ca al l
O
Ox xy yg ge en n P Pr ro ob be e
D
Da at ta a S Sh he ee et t
S423/C/OPT Optical oxygen p obe – Data Sheet 11
Composition of the supply
The supply consists of a single package containing the following parts:
1. 1 S423/C/OPT Optical Oxygen Probe with a 10 m cable
2. 1 Technical Manual for instructions
Electric installation
Turn off the instrument, connect the cables of the probe to the terminal block
of the meter. Please observe the colors shown on the sticker located under
the electronic cover of the instrument or refer to the chart below.
The measuring sensor is supplied with 10m cable kit, for connections at
greater distances do not exceed 1000m cable. Do not run the cable near high
power cables or inverter in order to avoid problems of noise on the
measurement.
RED +12V …24V
BLACK GROUND
YELLOW A+ RS485
GREEN B- RS485
21

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S4 42 23 3/ /C C/ /O OP PT T O Op pt ti ic ca al l
O
Ox xy yg ge en n P Pr ro ob be e
D
Da at ta a S Sh he ee et t
S423/C/OPT Optical oxygen p obe – Data Sheet 12
Hydraulic installation
The S423/C/OPT probe is supplied with a circular ip67connector for the
connection to the 42 and 50 series units, and can be provided with the
appropriate probe holder S315 / O, available in various tube lengths.
Together with the probe holder is provided a device for positioning the probe
at 45°.
It is also possible to equip the assembly with a swivel system that provides
the ability to get almost any configuration, as well as easier cleaning and
maintenance of the system (see figure below).