Hello everyone, thank you for your patience while I conferred with the chemistry department. There have been several issues raised, and I will do my best to address them all here. Please let me know if I have missed anything or not explained it to your satisfaction.
bbart12 said:
This brings up some interesting problems for hanna chemists.
1) Can you design a the regent to effectively change based on the amount of the chemicals you are testing in the sample.
2) Are these compounds stable over time.(this is I think why the regents are individually packaged)
3) How is this reaction influenced by things such as temp and ph and all of the other things in the sample.
1) Yes. Each photometer has a specific range, which dictates the amount of reagent used for that test.
2) Yes. Each packet is stamped with an expiration date. Powder reagents are generally shelf stable for at least a couple of years.
3) We have used specific compounds to negate pH and temperature interferences.
Regarding the method:
Obviously, we cannot release proprietary methods/chemicals for our competitors to copy. This is why the MSDS for any product of any instrumentation company only gives the necessary safety information.
When designing the HI 755, our team used Standard Methods for testing total alkalinity as the reference method. Every HI 755 we have shipped and all the reagents lots were exhaustively tested against standards for total alkalinity, using commercially available artificial seawater, with a laboratory grade auto-titrator. Several hundred titrations were performed, and the HI 755 was dead on accurate every time.
Regarding the caps:
Anyone with a leaking cap, please send me a PM and I will take care of it.
Regarding the reagent packets:
You have all made some excellent suggestions on how to improve this. We are already looking into alternative packaging, but making this kind of change takes research and time.
We take all your concerns and suggestions very seriously, and we want nothing but satisfied customers. The chemistry department is at this very moment testing several commercially available alkalinity test kits and at least one standard that are used in the marine aquaria hobby, to verify their accuracy with an auto-titrator. We are confident in the accuracy of the meter we have produced, and hope that the data we produce today will assuage any doubts the exist.
Thanks
Jessica
