Hach-Lange LDO Sensor - Manual (Page 11)

Configure linear output on the controller
Linear outputs send probe data back to the facility PLC, SCADA or other data collection system.
1. Go to the controller output setup menu.
Option Description
sc200 Go to MENU>SETTINGS>sc200 SETUP>OUTPUT SETUP>[Select Output]>SET FUNCTION.
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 Description
sc200 LINEAR
sc100 LINEAR CONTROL (Default value)
sc1000 LINEAR CONTROL (Default value)
Modbus registers
A list of Modbus registers is available for network communication. Refer to www.hach.com or
www.hach-lange.com for more information.
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 2 shows options for calibration.
Table 2 Calibration options
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
Calibration with air
User notes:
• Make sure that calibration bag has water inside.
• Make sure that the seal between the calibration bag and the sensor body is tight.
• Make sure that the sensor is dry when it is calibrated.
• Make sure the air pressure/elevation setting is accurate for the calibration location.
• Allow enough time for the sensor temperature to stabilize to the temperature of the calibration bag
location. A large difference in temperature between the process and the calibration location can
take up to 15 minutes to stabilize.
1. Remove the sensor from the process. Use a wet cloth to clean the sensor.
2. Put the entire sensor in a calibration bag with 25-50 mL of water. 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 (
Figure 6 ).
3. Use a rubber band, tie or hand to create a tight seal around the sensor body.
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