Hanna Instruments HI-781-25 Marine Low Range Nitrate reagents, 25 tests
HI-781-25 Marine Low Range Nitrate reagents, 25 tests
HI-781-25 Marine Low Range Nitrate reagents, 25 tests, for use with the HI-781 Nitrate Handheld Colorimeter Checker.
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 HI-781A-0 reagent into the large mixing vial.
- Add the content of one packet of HI-781B-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 10mL syringe until the 10mL 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 HI-781C-0 reagent. Replace the cap and shake vigorously for 2 minutes.
- Insert the cuvette into the checker.
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.
Four steps. One click. Instant Readout.
1. ‘Zero’ the Checker®HC with your vial inside
2. Place a 10ml water sample into the vial and add your reagent
3. Place your vial into your Checker®HC
4. Press the button and read the results
Use HI-781-11 Calibration Check Set with the HI-781.
Frequently Asked Questions
Clear answers to help you choose the right water testing solution with confidence
Which brands of water testing kits do you supply?
Do you provide kits for both home and professional use?
Yes — whether you’re a pool or spa owner, aquarium keeper, utility company, or a university laboratory, we have the right solution for your needs.
Can I arrange servicing or calibration for my photometer?
Absolutely. We also provide servicing and calibration to keep your photometers accurate and reliable.
How quickly do you dispatch orders?
Orders placed before 2:30 pm (Monday–Friday) are dispatched the same day. We also ship on Saturdays for your convenience.
Which couriers do you use for delivery?
We deliver through UPS, DPD, and Royal Mail. You can also choose to upgrade to next-day delivery at checkout.
What is your return policy?
We accept returns within 14 days of delivery provided the items are unused, in their original packaging, and in resalable condition. Please contact our team before returning any items.
Can I place bulk or business orders?
Yes, we welcome bulk, trade, and institutional orders. For tailored pricing or large quantities, please get in touch with us directly.
How can I get help if I’m unsure which kit to buy?
You can call us at 📞 +44 (0)115888 2726 and our team will guide you in choosing the most suitable kit for your needs.