Analog Output; Figure 5-13: Wiring The Analog Output - Fluke Endurance Series User Manual

5.7.2 Analog Output

The analog output can be set to 0-20 mA or 4-20 mA current range. Direct connection to a recording device (e.g.,
chart recorder, PLC, or controller) is possible. The total analog output circuit impedance is limited to 500 Ω.
For the principle wiring, use the installation scheme below.
A specific feature for the testing or calibrating of connected equipment allows the current loop output to be set to
specific values, under range or over range using a dedicated ASCII command. Via such functionality, you can force
the instrument, operating in the 4-20 mA mode, to transmit an output current less than 4 mA (e.g., 3.5 mA) or
above 20 mA (e.g., 21.0 mA).
Current Calculation
The sensor converts each measured temperature to a current equivalent. By default, the current equivalent
corresponds to the measuring range of the sensor. However, the current output can also be scaled to a subrange
defined by the user.
The following formula demonstrates the output current calculation regarding the given measurement subrange.
– upper temperature of subrange, e.g. 2000°C
T
Up
– lower temperature of subrange, e.g. 1000°C
T
Lo
– upper current of current output range, e.g. 20 mA
I
Up
– lower current of current output range, e.g. 4 mA
I
Lo
– actual measured temperature, e.g. 1500°C
T
Meas
– actual calculated and output current
I
Meas
I − I
Up Lo
∙ ( T
I = I +
Meas Lo
T − T
Up Lo

Figure 5-13: Wiring the Analog Output

Sensor
+ mA Out (J)
- mA Out (K)
Ground (L)
+ 24 VDC (M)
20mA − 4mA
) = 4mA +
− T
Meas Lo
2000°C − 1000°C
A
V
DC
+
∙ ( 1500°C − 1000°C ) = 12mA
Installation 5
Outputs
41