6. Calibration Instructions
The RT810 comes factory calibrated. If you need to re-calibrate the unit, you will
require the following equipment :
•
9-36 VDC Power Supply with a milliamp indicator or
a loop-powered calibrator.
•
A temperature bath.
•
A standard reference temperature sensor.
•
Test leads.
2 Point Calibration, Min. & Max.
( Example : 0-100 °C range )
1. Connect the RT810 as per the wiring diagram. ( 5 )
2. Set the temperature bath to the minimum range of the RT810 transmitter,
Ex.: 0 °C = 4.00 mA
3. With the temperature standard, verify the bath temperature and, if
required, calculate the corresponding current output for the RT810.
4. Immerse the RT810 probe in the temperature bath. Make sure the output
stabilizes. With ZERO pot. adjust current output to 4.00mA or the
corresponding current output.
5. Set the temperature bath to maximum range of the RT810 transmitter,
Ex.: 100 °C = 20.00 mA
6. With the temperature standard, verify the bath temperature and, if required,
calculate the corresponding current output for the RT810.
7. Immerse the RT810 probe in the temperature bath. Make sure the output
stabilizes. With the SPAN pot. adjust current output to 20.00 mA or the
corresponding current output.
8. Repeat steps 2 to 7 until required accuracy is reached. This step is necessary
because of the small interaction between Zero and Span.
Single Point Calibration
( Example : 0-100 °C range )
In some cases, a single point calibration is sufficient especially when a process is at
a fixed set point.
1. With a temperature standard, verify the correct process temperature and
compare it to the RT810 reading.
2. If the temperature reading is below the mid-point of the RT810 range, use
the ZERO pot. to obtain the correct reading.
3. If the temperature reading is above the mid-point of the RT810 range, use
the SPAN pot. to obtain the correct reading.
Power Supply
9-36V DC
4-20 mA
Indicator
Pt100
The diagram above represents the connection method to provide the 4-20 mA with
a current loop output. In most cases, the RT810 would take the form of a 3 wire
output probe assembly. The output loop, the indicator and the transmitter are
powered by a 9 to 36 VDC power supply. The indicator could be replaced by a
controller, a data logger, etc.
Note :
Transmitters are protected against reverse connections, incorrect
connections of the output wires result in a near zero current flow in
the loop.
5. Electrical Connections
4. Dimensions
1.75 ”
[ 44.45 ]
1.30 ”
[ 33.02 ]
0.35 ”
[ 8.89 ]
0.75 ”
[ 19.05 ]
Zero
Adjustment Pot.
Span
Adjustment Pot
.
3
2
W W R