Hach DR 5000 用户手册

e. Does the test require the sample to be at a certain 

temperature?

Was the pH of the sample in the correct range?

g. Is the pipette volume correct?

2. Check the used reagents by repeating the standard addition 

procedure with freshly prepared reagents.

If none of these measures resolves the problem, please contact the 
manufacturer or a sales representative.

Carry out the standard addition in accordance with the 
corresponding procedure.

There are two different methods:

Peak volume (Standard addition):
Defined volumes of a standard solution are added step by step to 
an already analyzed sample. The sample is measured again after 
each addition.

Sample volume:
A defined volume of a standard solution of known concentration is 
added to the volume of sample specified in the procedure and the 
sample is measured after each addition. In most cases three 
different standard solutions are prepared and the procedure is 
repeated for each of them.

100%

The originally used reagents were defective. 
Check the standard solution: 
Repeat the standard addition procedure with a 
freshly prepared standard solution.

100%

The originally used 
standard solution was 
defective.