Metrohm 870 KF Titrino plus Manual - Manual (Page 90)

10.8 Arithmetic algorithms in the 870 KF Titrino plus
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80 ￭￭￭￭￭￭￭￭
870 KF Titrino plus
Variable Comment
CONC Concentration of selected solution
FCT Factor
DIV Divisor
MCV End volume, i.e. total dosed volume at the end of the titration
EM1 Measured value of the endpoint EP1
ED1 Time at the endpoint EP1
MSV Start volume
DD Duration of the entire determination
The values of the variables are only available after the end of a determina-
tion (in the status 'ready').
Acknowledgement of
the instrument Comment
OK Command executed
E1 Method not found
E2 Invalid variable
E3 Invalid command
10.8 Arithmetic algorithms in the 870 KF Titrino plus
Numerical format
The software of the 870 KF Titrino plus calculates in accordance with the
widespread standard IEEE 754 (IEEE Standard for Binary Floating-Point
Arithmetic for Microprocessor Systems). This means that the numbers are
used in calculations in "double precision" (64 bit). Decimal numbers are
converted into binary numbers in the computer and used in this form for
calculations. The output on the display and in reports once again contains
decimal numbers; the binary numbers are thus converted back into deci-
mal numbers. In order to be able to check the internal calculations per-
formed by the computer yourself in accordance with IEEE 754, the num-
bers are reproduced in the calculation report in complete accuracy. A min-
imal difference may arise between an originally entered decimal number
and the internal computer representation in complete accuracy in the
range of the rear decimal places. This difference results from the fact that
an exact binary equivalent does not exist for every decimal number. If, for
example, you enter the sample size 50.3 mg, this will be depicted in the
calculation report in "double precision" with 5.02999999999999E+01.