Operating Instructions

13Operating Instructions VisiFerm
™
mA Sensors
INSTALLATIONPRODUCT DESCRIPTION
4.3 Optical DO measurement
The optical measurement principle is based on the so-called
luminescence quenching. The luminescence of certain organic
pigments (luminophore) is quenched in the presence of oxygen.
The luminophore absorbs the excitation light and release a part of
the absorbed energy by emission of fluorescence. In the pres-
ence of oxygen, energy transfer takes place from the excited
luminophore to oxygen. The luminophore does not emit fluore-
cence and the measurable fluorescence signal decreases.
O
2
O
2
1
2
Light (excitation)
Light Absorption Excited State
Luminophore
Fluorescence process (without oxygen)
Quenching in the presence of oxygen
Energy transfer
Light Absorption Excited State
Fluorescence
(emission)
No fluorescence
Figure 5: Fluorescence quenching by oxygen
4.4 VisiFerm mA with Micro-Transmitter inside
With the micro-transmitter integrated, VisiFerm mA sensors offer
fully compensated signal directly to the process control system.
Communication protocols include standard analog 4–20 mA or
digital HART. The micro-transmitter located in the sensor head
stores all relevant sensor data, including calibration and diag-
nostic information, simplifying calibration and maintenance.
5 Installation
5.1 Unpacking
1) Unpack carefully
the VisiFerm mA sensor.
Enclosed you will find the VisiFerm mA sensor, the
Declaration of Quality, the VisiFerm mA Operating Instructions,
and the Stainless Steel Inspection Certificate.
2) Inspect the sensor for shipping damages or missing parts.
4.2 Hardware Description
The VisiFerm mA sensor consists of a sensor head with inte-
grated electronic and a sensor shaft in contact with the measured
medium. The sensor shaft is terminated by the optical dissolved
oxygen (ODO) cap, carrying the oxygen sensitive luminophore.
During development, special attention was paid to an optimum
sanitary design.
Sensor status LED of the sensor:
LED Status Case
All LEDs light up shortly
one by one in a circle Power Up
Green LEDs are flashing Ready to operate, no errors or
warnings have been registered
Yellow LEDs are flashing Warning, minimum one
warning is active
Red LEDs are flashing Error, minimum one error is
active
All LEDs light up slowly Wireless communication to
one by one in a circle ArcAir is active
M12 Connector
Sensor Head with μ-transmitter
including Bluetooth antenna
Process connection
PG 13,5 stainless steel
O-ring
Sensor shaft with stainless
steel heat number and REF
ODO Cap with oxygen-sensitive
luminophore (sensing element),
ODO Cap serial number, Ref
number and stainless steel heat
number
Red LED / Yellow LED / Green LED
Protection Cap
ODO Cap H3
REF
10068400
LOT
1110 6 695 5
SN
114 3
2019-05-07
Figure 4: VisiFerm mA description