The HI781 Marine Nitrate Low Range Colorimeter is designed to accurately determine low range nitrate levels in saltwater aquariums and marine applications. With a digital read out, there is no more struggling to determine colors visually.
Range: 0.00 to 5.00 ppm (as NO3–) [0.0 to 50.0 ppm (calculated) using dilution]
Built-in timer so you don't miss a step.
The HI781 Checker®HC (Handheld Colorimeter) is a simple, accurate, and cost-effective way to measure nitrate from 0.00 to 5.00 ppm (as NO3–) in your saltwater aquarium. For samples containing 5.0 to 50.0 ppm nitrate, follow the approved dilution procedure.
Nitrate is a by-product of the Nitrogen cycle. Excessive amounts of nitrates in a reef aquarium can promote the growth of undesirable organisms including algae and dinoflagellates while insufficient amounts can lead to starvation in which SPS and other corals will show signs including the loss of color and paleness.
The HI781 Nitrate Checker HC is a handheld colorimeter that uses the Beer-Lambert principle to determine the concentration of nitrate colorimetrically. The HI781 is designed specifically to measure low levels of nitrate in a saltwater aquarium.
For use with saltwater samples.
More accurate than chemical test kits.
Dedicated to a single parameter.
Small size, big convenience.
No errors with a digital readout.
Ideal for aquariums and marine biology applications.
For samples containing 5-50 ppm nitrate, follow the dilution procedure.
Range 0.00 to 5.00 ppm (as NO3–)
0.0 to 50.0 ppm (calculated) using dilution
Resolution 0.01 ppm
Accuracy @ 25°C/77°F ±0.25 ppm ±2% of reading @ 25 °C (77 °F)
±2.5 ppm ± 5% of calculated reading using dilution
Light Source LED @ 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 checker has been developed to work with seawater samples.
Battery Type (1) 1.5V AAA
Auto-off after ten minutes of non-use
Environment 0 to 50°C (32 to 122°F); RH max 95% non-condensing
Dimensions 86.0 x 61.0 x 37.5 mm (3.4 x 2.4 x 1.5”)
Weight 64 g (2.3 oz)
Ordering Information Each HI781 is delivered in a case with custom insert and is supplied with: Marine Nitrate Low Range reagent starter kit (reagents for 25 tests), Sample cuvette and cap (2 pcs.), 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 mL graduated syringe (1 pc.), Plastic refilling pipette (1 pc.), 16 gauge blunt needle (1 pc.), 1.5V AAA Alkaline battery (1 pc.), and Instruction manual.
Reagent Set HI781-25 (25 tests)
Calibration Set HI781-11
Warranty 1 year