Tecfluid TH6 For AD Series - Manual (Page 4)

4
1 INTRODUCTION
The Halltec VI transmitter is an electronic position transducer with a microprocessor. The
instrument uses the Hall effect to capture the field of a magnet. This signal, after the micro-
controller processing, is converted into a current signal of 4-20 mA in a 2-wire loop. This
signal is proportional to the flow rate.
2 MODELS
2.1 TH6
It is a 4 to 20 mA transmitter proportional to flow rate. 4 mA corresponds to beginning of
the scale. 20 mA corresponds to full scale. Between the beginning of the scale and the first
point of the scale the analog output is constant at 4 mA, to avoid false readings of flow
rate.
1. Example: Response of the TH6 transmitter
2.2 TH6H
It is a TH6 transmitter that incorporates HART TM protocol compatibility. With this protocol
the user can change the measuring range of the 4-20 mA loop, and data like flow rate,
with its associated measuring units.
3 ELECTRICAL CONNECTION
For the electrical connection, the Halltec VI has two screw terminals.
For the electrical installation it is recommended to use multiple conductor cables with
individual cable sections in the order of 0.25 to 0.5 mm
2 in order to make it easier to
connect.
A twisted pair wiring should be used to avoid electrical interferences in the 4-20 mA loop.
In some instances, shielded cable may be necessary.
Before starting the installation, check that the cable glands are the right size for the cables
to be used, this will guarantee the instrument will stay watertight. The M12x1.5 cable
glands used are for cables with outside diameters between 2.5 mm and 6.5 mm.
Peel the outside insulation to free the inner cables. It is recommended to tin the ends of
the wires to avoid loose ends. Pass the cables through the cable glands and screw down
in the corresponding positions of the terminal strip. Once the wiring is finished make sure
that the cables are well gripped by the cable glands to maintain the degree of protection.
The cable glands must be always closed. Entry of dust or some types of vapours can
damage the internal system of bearings and therefore the equipment.
First point of
the scale
Last point of
the scale
Flow rate