HI-782-25 Marine HR Nitrate Checker Reagents

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.
• Fill the cuvette with 10 mL of unreacted sample 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 HI-782-0 Marine Nitrate High Range reagent. Replace the cap and shake vigorously for 2 minutes.
• Insert the cuvette into the checker and close the cap. Press and hold the ON/OFF button. The display will show the countdown prior to the measurement. Alternatively, wait 7 minutes and press the button.
• When the timer ends, the checker will perform the reading. The instrument displays the nitrate concentration in ppm. The checker automatically turns off 10 minutes after readings.

Tip for an accurate measurement

It is important that the sample does not contain any debris.

Whenever the cuvette is placed into the measurement cell, it must be dry outside and completely free of fingerprints, oil or dirt. Wipe it thoroughly with HI-731318 or a lint-free cloth prior to insertion.

Shaking the cuvette can generate bubbles, causing higher readings. To obtain accurate measurements, remove such bubbles by swirling or by gently tapping the cuvette.

Do not let the reacted sample stand for too long after reagent is added, or accuracy will be lost.

After the reading, it is important to discard the sample immediately, otherwise the glass might become permanently stained.