Operating Instructions

11Operating Instructions VisiFerm
™
mA Sensors
PRODUCT DESCRIPTIONSAFETY PRECAUTIONS AND HAZARDS
Option 2: Glass or plastic tank
(not connected to earth)
The glass or plastic tank has no connection to earth and
therefore it is necessary to connect the sensor shaft via a
screw clamp to earth.
X
Figure 2: Glass or plastic tank with no earth connection
Below are shown several examples how to connect the shaft of
the sensor directly to earth as required in Figure 2.
External earth cable
Figure 3: Example clamps for connecting the earth to armature and metallic
housing of the tank
3.4 Electrical Safety Precautions
Do not connect the sensor to a power source of any voltage
beyond the range stated in the Technical Specifications
(www.hamiltoncompany.com).
Always use Hamilton M12 cables for safe connection. Cables are
available in a broad range of lengths (Chapter 10). Make sure the
cable is intact and properly plugged to avoid any short circuit.
Keep VisiFerm mA away from other equipment which emits
electromagnetic radio frequency fields, and minimize static
electricity in the immediate environment of the optical measuring
parts. Carefully follow all the instructions in chapter 5.3 to avoid
electrical damage to the sensor. The contacts must be clean
and dry before sensor is connected to the cable.
ATTENTION! Switch off the power supply and
unplug the connector before dismounting the
VisiFerm mA.
ATTENTION! If the power supply (220 VAC/24VDC)
is switched off or disconnected the reading on the
PCS is wrong.
3.5 Chemical, Radioactive or Biological
Hazard Precautions
Selection of the appropriate safety level and implementation of
the required safety measures for working with VisiFerm mA is the
sole responsibility of the user.
If working with hazardous liquids observe and carry out the
maintenance procedures, paying particular attention to cleaning
and decontamination. If VisiFerm mA becomes contaminated
with biohazardous, radioactive or chemical material, it should
be cleaned. Failure to observe and carry out the maintenance
procedures may impair the reliability and correct functioning of
the measuring module.
4 Product Description
4.1 General Description
The VisiFerm mA is an optical dissolved oxygen (DO) sensor for
use in explosive environment. With their integrated transmitter,
VisiFerm mA sensors enable direct communication to the pro-
cess control system via 2 wire 4-20 mA standard signal or digital
HART. Wireless communication directly from the sensor may be
used for monitoring, configuration and calibration, and saves time
without compromising the quality of the wired connection. The
sensor features furthermore an integrated Bluetooth 5, enabling
in this way wireless encrypted data exchange with mobiles
(Android and iOS).
VisiFerm mA optical technology improves the measuring per-
formance and simplifies maintenance. Improvements compared
to conventional electrochemical (amperometric) sensors include
flow independence, rapid start-up with no polarization time, and
simplified maintenance.
With the transmitter integrated, VisiFerm mA sensors provide
more reliable measurements directly to your process control
system. The µ-transmitter located in the sensor head stores all
relevant sensor data, including calibration and diagnostic informa-
tion, simplifying calibration and maintenance. The integrated
quality indicators predicts the remaining sensor and cap lifetime.
Key benefits include:
• Optical measurement in explosive environment with
ATEX / IECEx certification
• No separate transmitter needed
• Simple maintenance with robust industrial design
• Easy to install 2-wire connection
• Direct analog or digital HART communication to the
process control system via 2 wire 4-20 mA standard signal.
• Full online wireless option via Bluetooth 5 for easy
monitoring, configuration and calibration
• Encrypted data exchange with mobiles (Android & iOS)