Burkert Type 8620 - Manual (Page 63)

mxCONTROL Type 8620
Page 63
Scaling
ScalDir = Rise:
Scal+ High scaling value, assigned to the
maximum current (20 mA)
Scal- Low scaling value, assigned to the
minimum current (4 mA)
ScalDir = Fall:
Scal+ High scaling value, corresponds to
the minimum current (4 mA)
Scal- Low scaling value, corresponds to
the maximum current (20 mA)
Figure 17: Scaling of a 4…20 mA input
The scaling function assigns a numeric value to the measured analog value, that corresponds to the
physical parameter transmitted to the device by the sensor/transmitter.
For displaying purposes an engineering unit can be assigned to the input. The following table lists the
available units, selectable for each 4...20 mA input separately.
Unit Group Measuring units (*)
Miscellaneous ppm, V, mA, Pulse, Hz, %, no unit?
Chemical Analysis µS/cm, mS/cm, MPY, µMPY, mV, mg/L, %Sat, pH
Volume L, hL, m3, Gal US; bbl US, gal Imp, ft3, yd3
Flow (flow rate) L/s, L/min, L/h, m3/min, m3/h, Gal/s US, Gal/m US, Gal/h US, gal/s Imp, gal/m Imp,
gal/h Imp, bbl/s US, bbl/m US, bbl/h US, ft3/s, ft3/min, ft3/h, P/s, P/m
Temperature °C, °F, °Rank, K
Pressure bar, mbar, psi
(*) If the display does not have sufficient spaces available, only 3 or 6 digits are shown; please refer
to the table in chapter 5.2 for the specific unit abbreviations.
If such a fault occurs, the common alarm output is activated.
Additionally, the safety output value will be activated in the corresponding modules, which
support the safety output function and which are linked with the faulty input.
If the safety output value is activated the manual output value will be reset to “0”!
If the scaling unit of a 4…20 mA input was changed, the corresponding alarm and warning
limits
and the set points of the corresponding modules have to be changed manually to the
value corresponding with the new engineering unit of the input (no automatic conversion from
one unit to a different one!).
When changing the scaling values, the corresponding alarm and warning limit as the set
points of the corresponding modules should be examined for their relevance!