Calibration Procedure - Hach FT660 sc Grundlegende Bedienungsanleitung

• Gently invert the bottle for 1 minute (about 50 inversions). Do not shake.
Note: The suspension is stable for 30–60 minutes after mixing.
The StablCal Certified Standard is stabilized formazin with a value that is identified to within ±
1 mNTU. The value, specific to that particular lot of product, is printed on the label. Lot-to-lot variation
will be ± 50 mNTU from the standard value, with a standard deviation of less than ± 5% within a
single lot.
Calibration notes
• Calibrate the instrument before initial use.
• Calibrate the instrument every three months (or as set by regulatory agencies).
• Calibrate the instrument after any significant maintenance or repair is done on the instrument.
• Always clean the instrument immediately before calibration. Refer to
on page 20.
• Operate the instrument at least 10 hours before calibration.
• For the best calibration, calibrate the instrument when it is at the same temperature as the
operating conditions.
• The Hold Outputs feature is automatically enabled during the zero electronics and calibration
procedure. The Hold Output feature holds attached outputs at the before-calibration settings.

Calibration procedure

1. From the Main menu, select Sensor Setup, [Select Sensor], Calibrate, StablCal Cal.
2. Select the available Output Mode (Active, Hold or Transfer) from the list box and confirm.
3. Remove the head assembly and bubble trap cover from the body of the instrument. Refer to
Figure 7.
4. Make sure that the body of the instrument is drained completely.
5. Enter the turbidity value that is on the label of the StablCal Standard bottle and confirm.
6. Put a funnel at the end of the bubble trap and slowly put 800 mNTU StablCal Standard in the
funnel to fill the body. Refer to
7. Put the bubble trap cover and head assembly on the body of the instrument.
Note: If the head assembly is not correctly installed, the laser will not turn on and the reading on the display will
be near 0.000 mNTU or a negative value. The red status light on the instrument will also flash one time per
second.
8. When the turbidity reading is stable (and after greater than 5 minutes), confirm to accept the
reading.
9. When the display shows "GOOD CAL! GAIN: X.XX ENTER TO CONT.", confirm to save the
turbidity value.
Note: If the display shows "BAD CAL!", confirm to do the calibration again or exit.
10. When the display shows "VERIFY CAL?", confirm to do a calibration verification or exit without
verification.
11. Do a calibration verification or enter the operator initials to complete the calibration.
12. When the display shows "RETURN SENSOR TO MEASURE MODE", confirm.
Figure 7.
Clean the instrument
English 13