Setting The Beginning And End Of The Measuring Range - Gossen MetraWatt KINAX WT 710 Mode D'emploi

Bridge
–
R
R
ext
ext
+
+ –
A and H
2-wire connection 3-wire connection
(4...20 mA) (different
mA-signals)
A = Measuring output...
... as 2-wire connection (4...20 mA, signal in
output/powering circuit)
... as 3 or 4-wire connection (different
mA-signals)
H = DC power supply H = 12...33 V
resp. H = 12...30 V with Ex version
R = External resistance
ext
Fig. 8. Connection diagrams for 2, 3 or 4-wire connection,
without electric isolation, DC power supply.
+ –
+
R
ext
–
A
4-wire connection (different mA-signals)
A = Measuring output
H = DC/AC power supply
R = External resistance
ext
Fig. 9. Connection diagram for 4-wire connection, with electric
isolation, DC/AC power supply.
8. Setting the beginning and end of the
measuring range
The coarse adjustment of the beginning of the measuring
range consists in aligning the zero of the measured device
with the external zero mark on the transmitter. The procedure
was described in Section 6 "Mounting". This Section concerns
the fine adjustment not only of the beginning of the range
(ZERO), but also of the end of the scale (SPAN).
+
+
R
ext
–
–
– +
+ –
A H
A H
4-wire connection
(different
mA-signals)
+ –
+ ~ – ~
H
Firstly, switch on the power supply to the transmitter.
Take off the cover from the housing.
Caution! The screw terminals (2.1) Fig. 7
are live.
The 230 V power supply is potentially
dangereous
Place themeasured device at its zero position, i.e. the
position at which the KINAX WT 710 should produce 0 mA (3
or 4-wire connection), respectively 4 mA (2-wire connection)
at its output.
Should the output current differ by more than 2% from its
initial value, repeat the coarse zero setting procedure
described in Section 6 "Mounting".
Then adjust the "ZERO" potentiometer (Fig. 10 resp. Fig. 11)
using a watchmaker's screwdriver (2.3 mm diam.) so that the
desired output current flows.
ZERO
Fig. 10. Housing (1) with the adjustments
"ZERO", "SPAN" and "S1".
ZERO
Fig. 11. Housing (1), version with power pack, with the
adjustments "ZERO", "SPAN" and "S1".
Now rotate the measured device to its opposite limit position,
i.e. the position at which the KINAX WT 710 should produce
the prescribed full-scale output current (see rating plate).
Adjust the "SPAN" potentiometer with the screwdriver as
before until precisely the prescribed full-scale output current
is measured at the output.
The recheck the zero point and correct on the ZERO
potentiometer if necessary. Check the full-scale value again.
Repeat both adjustments until both zero point and full-scale
value are precise.
(1)
SPAN
S1
(1)
SPAN
S1
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