Checker Hanna HI781 nitrate Low Range – Review and video

ENG- Checker Hanna HI781 nitrate Low Range - Review and video
The colorimetric Checker Hanna HI781 is the newest of the Marine Line

We knew that Hanna Instruments recently announced the release on the market of a new colorimetric for low-range nitrates (NO3) in marine water, and we mentioned in our article back to June (here the link for the italian article).

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This article is also available in: italiano

From the evening of November 14th the Checker HI781 Nitrate LR entered officially the selling list of the company. We of DaniReef waited for it on extremely curiosity and a bit of impatience. Finally we have it in our hands and we want to share our first impressions. But, before presenting this little lilac egg, we want to introduce the company.

An Italian excellence

Maybe not everyone knows that the Hanna Instruments srl is an italian company. It was founded in 1978 in Limena (a small town near Padova) by Oscar and Anna Nardo, is actually run by their son Martino. The company has grown internationally thanks to the union of innovation and reliability, until they became the world leader of analysis equipments. Since a few years the company has started to sell colorimetric checkers, often knew as “eggs“, devices devoted to the measurement of certain parameters of the water, that attracted interest of the whole aquaristic world.

Until some years ago the only devices that did the most precise measurement were the phosphate photometers. This devices, anyway, had very high prices so less diffused, unless you’d like to spend almost 300 euro for a semi-professional phosphate photometer. But the real breaking point with the countless testers on the market was the accuracy of the measurement, the ease of use and especially the univocity of the lecture. In fact, almost all the normal testers based on colorimetric comparison have the fault to mislead the user due to external factors.

The same test can give different results if it’s done in the sunlight or in artificial light. The user’s eye may discriminate differently the color gradations leading to a wide range of results. Some differences can be very accentuated among users, each having their own unique visual sensitivity. 

For this, having a tool quite cheap (the fixed price is € 55 + IVA on Hanna’s official site), with an ease of reading like this and with univocity of results are enough reasons why these eggs enjoyed so much success among us.

The Checker Hanna HI781 for low range nitrates in salt water is the last arrived in the long list of the catalog of Hanna Marine Line. It keeps the characteristics and the pros of its predecessors, but it fills an old gap, the measurement of the NO3 nitrates.

Let’s see in detail.

The package of the Checker HI781, with the classic suitcase in black and rigid plastic
The package of the Checker HI781, with the classic suitcase in black and rigid plastic

Our presentation video

We also did a useful video of introducing to the Checker HI781 and a guide for obtaining the perfect measurement. The video is in italian, but you can activate the subtitles.

The main features

The Checker HI781 is in all respects a photometer. Hanna studied a system for containing the costs: it uses a LED source with a fixed wave length (525 nm) and a silicium photocell for the detections.

The tool is a meter for low range nitrates, that are from 1 to 5 ppm (parts per million) and the use if for salt water specifically. It exists a dilution procedure that allows to widen the measurement range from 5 to 50 ppm but this, obviously, decreases the accuracy of the result.

The solution in the range of the nominal functioning is of 0,01 ppm while the accuracy is +/- 0,25 ppm +/- the 2% of the reading done at a temperature of 25° C. It decreases at +/- 2,5 ppm +/- il 5% of the reading in case of dilution.

Let’s say that the f you want to understand better the accuracy of this tool know that we contacted the assistance of Hanna Instruments, that clarified every doubt fast and professionally.

So let’s do a practical example:

Let’s say that at the end of a low range measurement (so without dilution procedure), done at 25° C, the tool gives a value of 5.00 ppm. That means that the real value of nitrates can be any between 4,65 and 5,35 ppm, that is 5.00 ppm more or less the error of 0,25 ppm to which you is added or subtracted a value calculated on the reading, of 0,1 ppm, that is the 2% of what shows on the display. Of course this induced error decreases gradually approaching the 0.0. In case of a reading of 0.0 ppm, the real value of nitrates may be between 0 and 0,25 ppm, and you can totally ignore the incidence of 2%.

In truth we had some difficulties in the readings close to 0. Considering this range the device doesn’t show the real values, sticking with 0.0 ppm even if the coloration of the compost under investigation was visually different in the mensurations. In these cases the declared error is more noticeable, where you have solutions with nitrates very close to 0, but not completely absent.

In conclusion, I think that this reading is pretty accurate for our needs, especially if we consider that the main part of the classic test only manage to discriminate integer values and quite distant, like 1, 5, 10 ppm and so on.

The article continues on page two where you can find the cost, see the unboxing and download the manual.

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