Hanna Instruments HI 93414 User Manual
Page 27
27
MULTIPLE SAMPLES READ
• Place the second cuvette with the reacted
sample into the holder and ensure that the
mark on the glass is matched with the mark on
the instrument top.
• Hold
READ/TIMER for 3 seconds. The
display will show the hourglass blinking and
the countdown prior to measurement.
Alternatively wait for:
Free Chlorine
Total Chlorine
1 minute or 2 minutes and 30 seconds
and then just press
READ/TIMER .
• In both cases blinking dashes will appear during
measurement.
• The instrument directly displays the concentration
in mg/L of free or total chlorine.
Note: It is recommended to make a zero before
each measurement.
Note: If the signal to noise ratio is too high, the
zero value will blink.
INTERFERENCES
The colorimetric measurements are affected by the following interfering agents:
• Bromine (positive error).
• Chlorine dioxide (positive error).
• Iodine (positive error).
• Oxidized Manganese and Chromium (positive error).
• Alkalinity above 250 mg/L CaCO
3
or acidity above 150 mg/L CaCO
3
will not reliably develop the
full amount of color or it may rapidly fade. To resolve this, neutralize the sample with diluted HCl
or NaOH.
• In case of water with hardness greater than 500 mg/L CaCO
3
, shake the sample for approximatively
2 minutes after adding the powder reagent.
or