Hach-Lange SURFACE SCATTER 7 sc Turbidimeter - Manual (Page 33)

31
Operation
5.5 Sensor calibration and verification
5.5.1 Standardization and calibration
DANGER
To become familiar with handling precautions, dangers and
emergency procedures, always review the Material Safety Data
Sheets prior to handling containers, reservoirs and delivery
systems that contain chemical reagents and standards.
Protective eye wear is always recommended when contact
with chemicals is possible.
Note: Due to the ease with which the calibration cylinder method
calibration can be performed, better accuracy can be maintained by
performing a calibration at monthly intervals instead of the standardization
check. Periodic calibration with a formazin primary standard is
recommended for best absolute accuracy.
5.5.2 Calibration
The manufacturer recommends calibrating the Surface Scatter 7 sc
instrument at least every three months or any time the light source
is replaced or adjusted. If calibration is performed with a formazin
standard, refer to
section 5.5.2.1 on page 32 .
1. From the Main Menu, select SENSOR SETUP and confirm.
2. If multiple sensors are attached to the controller, choose
SELECT SENSOR>SS7 SETUP and confirm.
3. Select CALIBRATE and confirm.
4. Select PERFORM CAL and confirm. Select the available
Output Mode (Active, Hold or Transfer) and confirm.
5. Enter the STD VALUE and confirm. Confirm to continue.
6. Follow the display prompt and place standard into the
calibration cup. Close the sensor door and confirm to continue.
7. The TURB value displayed is the standard value determined
using the gain from the previous calibration. Confirm to accept
and continue with the calibration.
DIAG/TEST
INST STATUS Displays the software and hardware versions.
SERIAL NUMBER Displays the serial number of the sensor.
INT TEMP Displays the internal temperature of the sensor electronics in °C.
DEFAULT SETUP Restores the sensor factory default settings. Calibration is not affected.
POWER CHECK Displays the electrical statistics for the sensor.
SERVICE MODE
Allows SS7 sc to be run in normal or service mode. Analog outputs can be in ACTIVE, HOLD or
TRANSFER mode. Data logging is disabled. Protected by MAINTENANCE password.
SERVICE DIAG Accessible with service password only.
5.4 Sensor setup menu (continued)