Chino AL3000 SERIES, Instructions Manual

Page: 88 / 116

15-2
15.2. Shunt Resistor for Current Input
A DC current input can be measured by connecting a shunt resistor (option) to the input terminals and
converting the current input into a voltage level.
1. Shunt resistor (option) and
measuring current range
･
A shunt resistor converts a DC current input
into a DC voltage. Two kinds of resistors are
available as shown in the right table.
･
The measuring current ranges by two kinds of
shunt resistors are as specified in the right
table.
2. Connections
Connect a shunt resistor to each measuring
channel for a DC current input.
3. [Range/printing range]
and [scale]
1) Range number
Range number is 07, since the conversion
voltage by each shunt resistor is
±
5V.
2) Printing range
Program the printing range by the
voltage-converted value.
･
Lower-limit value = Lower-limit current
×
shunt resistor's value
･
Higher-limit value = Higher-limit current
×
shunt resistor's value
3) Scale
Program the scale by the physical quantity to
a current input.
･
Lower-limit value = Physical quantity of the
lower-limit current
･
Higher-limit value = Physical quantity of
the higher-limit current
Code
Resistance
value*
Measuring range
BZ-RX100 100 Ω ±50mA DC
BZ-RX250 250 Ω ±20mA DC
＊
Accuracy : 100
Ω
--- Rated value
±
0.05%
250
Ω
--- Rated value
±
0.1%
Shunt resistor and measuring range
Resistance
value
Measuring
range
Converted
voltage
Range
No.
100 Ω ±50mA DC ±5V DC 07
250 Ω ±20mA DC ±5V DC 07
Range number to be used
<Desired trace printing input 4 to 20mA>
Use 250
Ω
shunt resistor, since the maximum
measuring current is 20 mA.
･
Lower-limit value = 4(mA)
×
250(
Ω
) = 1(V)
･
Higher-limit value = 20(mA)
×
250(
Ω
) = 5(V)
Printing range example
<Physical quantity of 4 to 20 mA is 0 to 500 / m
2
>
･
Lower-limit value = 0
･
Higher-limit value = 500
An example of scale programming
Connect one shunt resistor to one channel.
Cautions on connections
Remarks
+
-
Channel
1
100 Ω or
250 Ω
Shunt resistor
Measuring
current source
Recorder
<Example> Connect a shunt resistor to channel 1
+
-