Hach-Lange SURFACE SCATTER 7 sc Turbidimeter - Manual (Page 38)

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Operation
9. When the displayed turbidity value is stable, confirm to select
the measured reading. After confirming the reading:
• GOOD VER! will be displayed if the verification is good,
with an option to continue or to abort. Confirm to continue.
Enter the operator initials and confirm.
• BAD VER! will be displayed if the verification is bad, with an
option to repeat or exit. To repeat the verification, confirm to
return to the VALID SN screen (step
6 ).
10. Open the SS7 sc to remove the plate. Restart the sample flow
and close the door. Confirm to return the instrument to
measurement mode.
Note: After confirmation of return to measurement mode, the instrument
will equilibrate for 2 minutes before the output mode changes. Instrument
measurements will show on the display, but the value will flash and a “OUT
MODE WARN” warning will display until the 2-minute equilibration period
is complete.
5.5.4.1 Care of standardization plates
Clean standardization plates to remove fingerprints, dust and dirt.
• Clean plates using water and dry with a clean,
lint-free cloth.
• Do not use abrasive cleaners or cleaning solvents.
Store the plates in a clean, dry place to prevent scratching or
damage. Replace the plates if they become scratched or broken.
5.6 Calibration and verification history
The calibration and verification history logs contain information on
the last 12 calibrations and the last 12 verifications. The calibration
history log shows the gain value, the time and date of the
calibration and the initials of the operator performing verification.
Note: Restoring default settings from the DIAG/TEST menu will return the
turbidimeter to its non calibration state (gain = 1.0) but it will not remove the
previous calibration history from memory.
The calibration history log is accessed from the Calibrate menu.
The verification history log is accessed from the Verification menu
(a submenu of the Calibrate menu).
Each verification history entry shows the serial number of the
verification device, the value of the verification standard, the time
and date of the verification and the initials of the operator
performing the verification.
To view calibration history:
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 CAL HISTORY and confirm. The most recent calibration
will be displayed on the screen.