Calibration verification, Optical system check, Prepare a sample cell – Hach-Lange 2100 N IS Laboratory Turbidimeter User Manual User Manual
Page 18: Clean the sample cell, Calibration verification optical system check, Optical system check is done. refer to
Calibration verification
At intervals, measure the Gelex secondary turbidity standard that is
closest in value to the turbidity range to be measured. Do the steps in
Measure the Gelex secondary turbidity standards
on page 15, but do not
change the value that is recorded on the vial.
If the measured value is within ±5% of the value recorded on the Gelex
vial, calibration is verified. If not, calibrate the instrument.
Note: The StablCal
®
primary turbidity standards can also be used to do a
calibration check. Prepare the StablCal vials before use. Refer to
on page 11. Do not use the < 0.1 NTU StablCal vial as it does
not have an accurately identified NTU value. The instrument is calibrated if the
measured value is within ±5% of the StablCal value.
Optical system check
At intervals, measure the Gelex stray light standard to inspect the
integrity of the optical system. Do the steps in
on page 14, but do not change the value that is recorded
on the vial.
If the value measured is similar to the value recorded on the Gelex stray
light standard (within ±0.02 NTU), the instrument works correctly. If not,
contact Customer Service.
Prepare a sample cell
Use a clean sample cell(s) for sample measurement.
Note: As an alternative, a flow cell can be used for sample measurement. Refer to
on page 26.
Clean the sample cell
C A U T I O N
Chemical exposure hazard. Obey laboratory safety procedures and
wear all of the personal protective equipment appropriate to the
chemicals that are handled. Refer to the current material safety data
sheets (MSDS) for safety protocols.
N O T I C E
Do not air dry the sample cells. Always store the sample cells with caps on to
prevent the cells from drying. For storage, fill the sample cell with distilled or
demineralized water.
1. Clean the internal and external surfaces of the sample cell and cap
with a laboratory glass cleaning detergent.
2. Fully rinse the sample cell many times with distilled or deionized
water.
3. Clean the internal and external surfaces of the sample cell and cap
with 1:1 hydrochloric acid.
4. Fully rinse the sample cell many times with distilled or deionized
water.
Note: If the sample cell will be used to measure low range turbidity samples or
dilution water, rinse with dilution water (not distilled or deionized water). Refer
to
on page 20.
5. Dry the external surface of the sample cell with a soft, lint-free cloth.
6. Fill the sample cell with distilled or deionized water.
Note: If the sample cell will be used to measure low range turbidity samples or
dilution water, fill the sample cell with dilution water (not distilled or deionized
water).
7. Immediately put the cap on the sample cell.
Note: Hold the sample cell by the top only to minimize dirt and fingerprints.
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