BUCHI KjelSampler K-377 - Manual (Page 101)

6 Operation
101 K-375/376/377 Operation Manual, Version B
(screenshot stretched)
Parameters for Back titration
Select
Back titration for the parameter “Titration
type“.
For the back titration the ammonia is collected in a
receiving solution of a strong acid. Afterwards the
remaining amount of the acid, that has not been
consumed for the neutralization of the ammonia,
is titrated back with a strong base. Therefore it is
important that the receiving acid solution is dosed
accurately.
NOTE
An additional second external dosing device must
be connected to the device to facilitate the accu-
rate addition of the receiving acid solution.
The receiving solution (strong acid) and the corre-
sponding titrant (strong base) can be selected from
the Volumetric solutions list (see chapter ”6.8.2
Volumetric Solutions”). The exact amount of the
provided receiving solution can be entered using
the “Receiving solution volume“ parameter.
In addition the stirrer speed for the titration and a
titration start volume can be specified. The speci-
fied titration start volume is dosed into the receiving
vessel previous to the titration.
(The sensor type cannot be changed for the back
titration.)
With the parameter Titration algorithm one of two
available algorithms for the titration can be selected:
Optimal: This algorithm has been optimized with
respect to the duration of the titration and the accu-
racy of the result. It is recommended to use the
optimal algorithm for back titrations of samples with
a low nitrogen content.
Normal: This algorithm has been optimized with
respect to the accuracy of the result but will require
a longer time than the optimal algorithm. The
normal algorithm is recommended for samples with
high nitrogen content and when using titration solu-
tions with high concentration (e.g. 0.5 N).