Hanna Instruments HI 83414 - Manual (Page 26)

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To enter calibration, press the CAL CHECK key
while in main screen. The first screen of GLP
information is displayed. Press the
Cal key to
start calibration.
It is possible to interupt calibration procedure at any time by pressing the
CAL CHECK key .
TWO-POINT CALIBRATION (Ratio and Non Ratio Turbidity)
• The first calibration point is displayed on the
LCD as 0.00 NTU. This point is used to check the
quality of the water used for dilution and to confirm
that the optical system is not dirty. If the value of
the first point is over 0.15 NTU, a warning “
Cal
Point1 high !” is displayed when the calibration
is saved and a warning “
Out of calibration range” is displayed when measurements under
10.0 NTU are performed.
Note: The reading of the first point can be skipped by pressing the Skip key. In this case, the
0.00 NTU point will be used for calibration.
• Place the <0.1 NTU standard cuvette (or the
cuvette with dilution water) into the holder and
ensure that the cuvette mark is aligned with the
sign on the instrument top.
• Close the lid and press the
Read key. The
display will show the value blinking and the lamp
icon during measurement.
Note: If the Average mode was previously
selected, the measurement in calibration
mode will be done using the average.
• At the end of the measurement, the second
proposed calibration point (15.0 NTU) is
displayed.
• Remove the first standard cuvette.
• Place the 15 NTU standard cuvette (or the
second formazin prepared standard) into the holder,
with the cuvette mark aligned with the sign on the
instrument top.
Note: If necessary, press
▲ or ▼ keys to edit
each calibration point value to match the
exact value of the standard as measured
with a reference turbidimeter.