Measurement Procedure
• Press the ON/OFF button to turn the checker
on. All segments will be displayed for a few
seconds, followed by “Add”
,
“C.1” with “Press”
blinking.
• Using the 10 mL syringe, measure exactly 7 mL
of sample into the large mixing vial.
• Using the 5 mL syringe, add exactly 4 mL of
HI781A-0
reagent into the large mixing vial.
• Add the content of one packet of
HI781B-0
reagent into the large mixing vial. Replace the
cap and shake vigorously for 1 minute.
• Remove the plunger from the 10 mL syringe.
Attach the syringe to the filter holder assembly
using the threaded connection.
• Remove the cap from the mixing vial. Hold
the syringe and filter holder assembly over
a cuvette. Carefully pour the contents of the
mixing vial into the back of the syringe.
• Very slowly push the plunger into the 10 mL
syringe until the 10 mL cuvette has been filled
up to the 10 mL mark and replace the cap.
Insert the cuvette into the checker and close
the cap.
• Press the ON/OFF button. When the display
shows “Add”
,
“C.2” with “Press” blinking, the
checker is zeroed.
• Remove the cuvette, unscrew the cap and
add the content of one packet of
HI781C-0
reagent. Replace the cap and shake vigorously
for 2 minutes.
• Insert the cuvette into the checker.
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Dear Customer,
Thank you for choosing a Hanna Instruments product. Please read this
instruction manual carefully before using the Checker
®
HC handheld
colorimeter. For more information about Hanna Instruments and our
products, visit www.hannainst.com or e-mail us at [email protected].
For technical support, contact your local Hanna Instruments Office or e-mail
us at [email protected].
Preliminary Examination
Remove the Checker
®
HC handheld colorimeter and accessories from the packing
material and examine it carefully. If you require any further information, please
contact Hanna Instruments technical support team.
Each
HI781
is delivered in a case with custom insert and is supplied with:
• Sample cuvette and cap (2 pcs.)
• Marine Nitrate Low Range reagent starter kit (reagents for 25 tests)
• Filter paper (25 pcs.)
• Filter holder (1 pc.)
• Mixing vial and cap (1 pc.)
• 5 mL syringe with tip (1 pc.)
• 10 mL syringe (1 pc.)
• 1.5V AAA Alkaline battery (1 pc.)
• Instruction manual
Note:
Save all packing material until you are sure that the Checker
®
HC
handheld colorimeter works correctly. Any damaged or defective item must
be returned in its original packing material with the supplied accessories.
General Description & Intended Use
HI781
Marine Nitrate Low Range handheld checker is designed to accurately
determine nitrate levels in aquariums and marine biology applications.
HI781
features a single-button operation system and is easy to use.
The large LCD is easy to read and the auto shut-off feature assures the battery
life will not be drained.
Specifications
Range
0.00 to 5.00 ppm (as NO
3
–
)
Resolution
0.01 ppm
Accuracy
±0.25 ppm ±2% of reading @ 25 °C (77 °F)
Light source
Light Emitting Diode @ 525 nm
Light detector
Silicon photocell
Method
Colorimetric method. The reaction between nitrate and the
reagent causes a pink/violet tint in the sample. This meter
has been developed to work with seawater samples.
Environment
0 to 50 °C (32 to 122 °F); max. 95% RH non-condensing
Battery type
1.5V AAA Alkaline
Auto shut-off
After 20 minutes of non-use and 4 minutes after reading
Dimensions
86.0 x 61.0 x 37.5 mm (3.4 x 2.4 x 1.5”)
Weight
64 g (2.3 oz)
Functional Description & LCD Display
Cap
Cuvette with cap
Cuvette holder
LCD (Liquid Crystal Display)
ON/OFF button
Prepare the Filter Holder Assembly
Unscrew the two halves of the reusable filter holder and carefully place one paper
filter on the lower piece (the lower piece has no threads on the outlet). Ensure the
filter paper is on top of the clear colorless gasket in the filter holder.
Thread the upper piece over the lower piece and tighten securely. Ensure that the
paper filter is not overlapping the threads.
The filter holder assembly is now ready for use.
• Press and hold the ON/OFF button. The display will
show the countdown prior to the measurement.
Alternatively, wait 8 minutes and press the button.
• When the timer ends the checker will perform
the reading. The instrument displays the
concentration of nitrate in ppm of NO
3
–
. The
checker turns off 4 minutes after reading.
Errors & Warnings
The checker shows clear warning messages when erroneous conditions appear and
when measured values are outside the expected range. The information below
provides an explanation of the errors and warnings, and the recommended action
to be taken.
Light High:
There is an excess amount of ambient light
reaching the detector. Please check the preparation of the zero
cuvette.
Light Low:
There is not enough light to perform a measurement.
Please check the preparation of the zero cuvette.
Inverted Cuvettes:
The sample and the zero cuvettes are
inverted. Swap the cuvettes and repeat the measurement.
Under Range:
A blinking “0.00”
indicates that the sample
absorbs less light than the zero reference. Check the
measurement procedure and make sure to use the same cuvette
for reference (zero) and measurement.
Over Range:
Maximum concentration value displayed blinking
indicates the measured value is outside the limits of the method.
Verify that the sample does not contain any debris. Dilute the
sample and repeat the measurement.
Battery Low:
Battery level is too low for the checker to function
properly. Replace the battery with a new one.
Drained Battery:
The battery is drained and
must be replaced. Replace the battery with a
new one and restart the checker.
