Hach LDO Benutzerhandbuch Seite 12

Option Description
sc100 Go to MENU>SYSTEM SETUP>OUTPUT SETUP>[Select Output]>SET FUNCTION.
sc1000 Go to MENU>SYSTEM SETUP>OUTPUT SETUP>[Select Output]>SET FUNCTION.
2. Set the function for the controller.
Option
sc200
sc100
sc1000
4.6 Modbus registers
A list of Modbus registers is available for network communication. Refer to the manufacturer's
website for more information.
Section 5 Calibration for measurements
The sensor is calibrated to specification at the factory. The manufacturer does not recommend
calibration unless periodically required by regulatory agencies. If calibration is required, let the sensor
come to equilibrium with the process before calibration. Do not calibrate the sensor at setup.
Table 3 shows options for calibration.
Option Description
AIR CAL Recommended calibration method. This calibration modifies the slope.
SAMPLE CAL Calibration by comparison with a hand-held DO meter . This calibration modifies the offset.
RESET DFLT CAL Resets the calibration gain (slope) and offset to the factory default: default gain=1.0; default
offset=0.0
5.1 Calibration with air
Air calibration is recommended for best accuracy and repeatability.
1. Remove the sensor from the process. Use a wet cloth to clean the sensor.
2. Put the cap end of the sensor in a calibration bag with 25-50 mL of water.
3. Attach the bag to the sensor body. Make sure that the sensor cap is not in contact with the water
inside the calibration bag and that no water drops are on the sensor cap. Refer to
4. Select MENU, SENSOR SETUP, LDO SETUP, [Select Sensor], CALIBRATE, AIR CAL, ENTER.
5. Select the option for the output signal during calibration:
Option Description
Active The instrument sends the current measured output value during the calibration procedure.
Hold The sensor output value is held at the current measured value during the calibration procedure.
Transfer A preset value is sent during calibration. Refer to the controller user manual to change the preset
value.
6. The controller will show "Move the sensor to air". Wait for the value to stabilize. The display will
show "Complete" and the slope correction. Push ENTER.
7. When the sensor is calibrated, put the sensor back into the process. Push ENTER.
12 English
Description
LINEAR
LINEAR CONTROL (Default value)
LINEAR CONTROL (Default value)
Table 3 Calibration options
Figure 6.