HI772 (dKH) vs HI755 (ppm) testing methods?

[Sleepydoc]

I was reading Dana Riddle's article comparing the results of the HI775 to the Hach pH titration for checking alkalinity and noted that the 771 and the 755 alkalinity checkers use different reagents. Since dKH vs ppm are the same thing on a different scale why do the two checkers use different reagents?

 

[Coral Me Impressed]

I could be wrong but I remember reading somewhere that Hanna said either reagent will work for either checker. I'll see if I can find it and put up a link.

 

[Coral Me Impressed]

Here is a video

 

[Hanna Instruments]

I was reading Dana Riddle's article comparing the results of the HI775 to the Hach pH titration for checking alkalinity and noted that the 771 and the 755 alkalinity checkers use different reagents. Since dKH vs ppm are the same thing on a different scale why do the two checkers use different reagents?

the HI772 and HI755 use the same reagent it is just a different part code.

 

[Sleepydoc]

great - thanks for confirming that!

 

[Valhalla Reefer]

the HI772 and HI755 use the same reagent it is just a different part code.

I understand that both Alk reagents can be used in the HI722 meter...but there wasn’t any mention of wether a conversation factor is needed afterwards to achieve dkh value using the HI755s reagent. (I seem to have bought caco3 instead of dkh reagent by mistake)

There’s something strange about my readings with the new reagent...and is what made me realize the difference in part numbers. Again, I understand reagents and checkers are interchangeable...I’d just like to confirm if conversion factors are necessary for either. #’s.

 

[GlassMunky]

I was reading Dana Riddle's article comparing the results of the HI775 to the Hach pH titration for checking alkalinity and noted that the 771 and the 755 alkalinity checkers use different reagents. Since dKH vs ppm are the same thing on a different scale why do the two checkers use different reagents?

They don’t.
The reagent for the ppm ALK test and the DKH alk test are the same

 

[GlassMunky]

I understand that both Alk reagents can be used in the HI722 meter...but there wasn’t any mention of wether a conversation factor is needed afterwards to achieve dkh value using the HI755s reagent. (I seem to have bought caco3 instead of dkh reagent by mistake)

There’s something strange about my readings with the new reagent...and is what made me realize the difference in part numbers. Again, I understand reagents and checkers are interchangeable...I’d just like to confirm if conversion factors are necessary for either. #’s.

No, no conversion is necessary. The checker already does that

 

[homer1475]

The only difference in the 2 checkers, one reports in DHK, the other reports in PPM. One does the math for you, the other requires you to do the conversion. Reagents are the same.

Very similar to the ULR phosphate kits. One reports in PPB, the other in PPM. One requires you to do the conversion, the other does the conversion(math) for you.

 

[Sleepydoc]

I understand that both Alk reagents can be used in the HI722 meter...but there wasn’t any mention of wether a conversation factor is needed afterwards to achieve dkh value using the HI755s reagent. (I seem to have bought caco3 instead of dkh reagent by mistake)

There’s something strange about my readings with the new reagent...and is what made me realize the difference in part numbers. Again, I understand reagents and checkers are interchangeable...I’d just like to confirm if conversion factors are necessary for either. #’s.

1 dkh = 17.9 ppm alkalinity but the Hana checker does the math for you so you shouldn’t need to worry about it. The reagent is the same solution just with a different label. If you are using one model it will give you the result in dKH, if you use the other it will give the result in ppm.

 

[Valhalla Reefer]

The only difference in the 2 checkers, one reports in DHK, the other reports in PPM. One does the math for you, the other requires you to do the conversion. Reagents are the same.

Very similar to the ULR phosphate kits. One reports in PPB, the other in PPM. One requires you to do the conversion, the other does the conversion(math) for you.

Ok. Appreciated thanks!