Hanna InstrumentsHI701 Checker HC Handheld Colorimeter for Free Chlorine

Is very ease of use and instructions are easy to follow. For those who are use to the old style of ppm total chlorine; remember this machine reads the free chlorine. If you have no prior experience with field water purification and testing or you work socking pools it won’t be second nature to you. For the later I know they will agree this is way easier. Also the reagent is a sold at a reasonable price.

Works well

I received the wrong product when I ordered, seller didn't try to contact me or correct the order, I had to return product and order again. I did not order from them again, I went straight to the product manufacturer.

Some instruments are purposely limited to encourage additional purchases. I believe this is one of those instruments. It appears there are several wavelengths and times for different measurements. The wavelengths are determined by the LED color while a resistor in the base of the unit apparently determines the countdown time. In summary, it means a single unit can be used to measure multiple parameters as long as the reagents and reaction times are correct.With two cuvettes, the free chlorine checker can be used for both free and total chlorine as well as other 525nm based tests. I tried this with free chlorine and total chlorine tests and think it is an excellent alternative to Taylor test kits. The Taylor kits (K2005 in particular) require matching light shades of pink to determine chlorine levels. Even holding up to light is not always conclusive and the measurement tolerance is roughly ±0.5 PPM.This meter yields an easy to read number. All the difficulties of pouring the reagent and setting the timer are eliminated if the user simply takes two samples, uses one as the control, and then manually times the wait period (1 minute for free chlorine, 2.5 minutes for total chlorine). Just before the time is completed, put in the unreacted sample, let the unit take the baseline measurement, and then insert the reacted sample and let the checker do its magic. I compared the results to the Taylor test kit and obtained relatively similar readings. The Taylor test kit I have is quite old and the reagents are well past expired (thus the reason for buying this checker). I also used this checker with the Taylor reagents and also obtained relatively similar readings. I purchased 100 test packs for both free and total chlorine so I am set for a while. Note that the Hanna reagents require pH less than 8.2. My pH was high and I did not get useable readings until I lowered the pH to below 8.0.This tester may also be used with other 525nm tests. I have a saltwater aquarium and wanted to check the phosphate/phosphorus levels. The HI 736-25 phosphorus reagents) measured 0.70 PPM. I don't have any algae problems so this seems reasonable. I recently ordered the HI 713-25 phosphate reagents and will compare the readings. I also have some HI 721-25 iron reagents but have not tested with it yet.If anything, I might recommend the Hanna Instruments HI 711 Total Chlorine checker for its 3.50 PPM range. The HI 701 is limited to 2.50 PPM. Both have 0.01 PPM resolution and ±0.03 PPM accuracy.

The Hanna HI 701 is a very nice little colorimeter and it works well. I was a little disappointed with some accessories. The opening to the bottle is so small it needs to be shaken to empty water from it. Also, the reagent package doesn't open very widely so it is tricky to pour the reagent without some of it spiling outside the narrow bottle opening.Overall I am happy with my purchase.

Works fine as a cheap alternate but shouldn't be your daily checker.Mines in for repairs so I bought this one while it's out.

Compared to the HI 729 Fluoride test, this one is really simple. You zero the device using your sample water before you add the reagent. Once it is zeroed, you add the powdered reagent, swirl it around for 20 seconds, then wait two minutes and thirty seconds for the test result.

Works better than my $700 hach unit that don’t last much more than a year