Metrohm 726 Titroprocessor User Manual

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7.10 Calculations / Formulas

726 Titroprocessor, Instructions for use

122

The test function TST( , )
If invalid values should occur during a calculation (e.g. missing endpoints)

the TST( ) function can still be used to obtain a correct calculation. The

syntax:

TST(variable to be tested, substitution term)

If the value of the variable specified is invalid in the calculation then this will

be carried out with the substitution term (variable or formula).

Examples:

•

In order to check the existence of an endpoint the TST( ) function can be

used in the following form:

R01=TST(EP1,0)*C01*C*157.45*100/SS

If no endpoint is present then the result R01 is not invalid. The correct re-

sult zero (0) will be shown.

•

If several equivalence points are expected in a titration it is recom-

mended that these are assigned to an EP window and that the calcula-

tion formulas are so defined that if an EP is missing all the calculations

are nevertheless carried out correctly. The following is an example of a

halide determination.

# Comment Formula (R$$, C##, X$$, EP# ...) Unit Dec Type

ДД ДДДДДДДДДДД ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД ДДДДДД ДДД ДДДДДД

1 Vol.iodide RV1=TST(EP1,0) mL 3 normal

2 Vol.bromide RV2=TST(EP2,RV1)-RV1 mL 3 normal

3 Vol.chloride RV3=TST(EP3,RV2+RV1)-RV2-RV1 mL 3 normal

4 Iodide RJ=RV1*C*126.9*1000/SS mg/L 2 stat.

5 Bromide RBR=RV2*C*79.9*1000/SS mg/L 2 stat.

6 Chloride RCL=RV3*C*35.45*1000/SS mg/L 2 stat.

Setting flags

Flags have the status true or false and are used to indicate a particular con-

dition or event. The status 'true' corresponds to the value 1 and the status

'false' to the value 0. In this way flags can be used for calculations.