Hach TL2350 Manuel D'utilisation De Base page 14

6.2.1 Calibration notes
• Make sure that the instrument is in the same ambient conditions as where it is used.
• Make sure that the standards are at the same ambient temperature as the instrument before use.
• Use only the provided silicone oil. This silicone oil has the same refractive index as the vial glass
and masks minor glass differences and scratches.
• Store the oiling cloth in a plastic storage bag to keep the cloth clean.
• If power is lost during calibration, the new calibration data is lost and the last calibration data is
used.
• In Calibration mode, automatic range and signal averaging on are selected. When calibration is
completed, all operational modes go back to the last settings.
• All nephelometric (turbidity units of measure) calibrations are done at the same time.
• Ratio-on and Ratio-off calibration data is measured and recorded at the same time.
• Clean the USEPA filter assembly before doing a primary calibration, or at least every 3 months
(which is the USEPA-recommended primary calibration interval).
6.2.2 Configure the calibration settings
Change the calibration settings as necessary before the instrument is calibrated. The instrument
must be calibrated when the calibration curve is changed.
1. Push Calibration.
2. Push Options>Calibration Setup.
3. Select the calibration curve range and type of calibration standard.
Option
StablCal RapidCal
(0–40 NTU)
StablCal (0–10000
NTU)
Formazin RapidCal
(0–40 NTU)
Formazin (0–10000
NTU)
Degrees (0–100 mg/L) Full-range calibration (20 mg/L, 100 mg/L and dilution water) with
SDVB (0–10000 NTU)
14 English
Description
Calibration with 20-NTU StablCal standard (default).
Note: The dark current in the instrument is used as the zero point of the
calibration curve. The calibration curve is linear from 0-40 NTU, thus low
turbidity measurements are very accurate.
Full-range calibration (<0.1 NTU, 20 NTU, 200 NTU, 1000 NTU,
4000 NTU, 7500 NTU) with StablCal.
Calibration with 20-NTU formazin standard.
Note: The dark current in the instrument is used as the zero point of the
calibration curve. The calibration curve is linear from 0-40 NTU, thus low
turbidity measurements are very accurate.
Full-range calibration (20 NTU, 200 NTU, 1000 NTU, 4000 NTU,
7500 NTU and dilution water) with formazin.
kaolin.
Full-range calibration (20 NTU, 200 NTU, 1000 NTU, 4000 NTU,
7500 NTU and dilution water) with spherical styrene divinylbenzene.