Tensiometer’s preliminary manual - TSS V1 r. 4 dtd 06/02/06
-11-
3.3
Earth connection – CE norms
In order to obtain the best immunity to electrical disturbs, are suggested the following
recommendations:
•
If instrument has an external power supply that is separated from the rest of the power
supplies, connect the “EARTH” terminal to a nearby earth connection of good quality.
•
In this condition remember that the signals obtained from the instrument (analog output
signal, RS232 serial connection, etc.) are connected to earth.
Verify not to create earth loops.
•
The best condition is obtained when all the power supplies are connected to earth in the
same point (quality of the used “earth connection” defines the immunity to disturbs).
•
Avoid to place the instrument’s connection cables near high power cable.
In case no high disturbs sources are present, it can
be avoided to use this earth connection .
NOTE: the external metal housing is electrically
connected to earth if this connection is used .
Removable screw terminal
Terminal
Use
1 Earth
connection
2
Analog output signal GND
3
Analog output signal 1-4 V
3.4
Amplified analog output connections
By connecting high impedance instrumentation to the screw terminal 2 and 3 it is possible to read
and acquire (strip chart recorders or data loggers) the pre-amplified analogue signal obtained by the
TSS transducer. This signal is characterized by a fixed gain and a zero regulation (around 1 V),
performed by the Pitagora instrument when “
C
” zeroing pushbutton is pressed. The zeroing
procedure takes some seconds to complete. The 1 to 4 V reference signals are to be considered
nominal. Each measuring system will have an individual signal dynamics and the conversion of
this signal into engineering units must be computer for each system.
