Metrohm 746 VA Trace Analyzer - Manual (Page 237)

5.5 Operation
746 VA Trace Analyzer / 747 VA Stand
5-86
Parameter Range; Default value / Meaning
In evaluations with standard addition (see section 6.9.4), MC.dev. is
calculated directly from the measured values of the sample and
standard additions. In evaluations with a calibration curve (see section
6.9.5) or internal standard (see section 6.9.6), MC.dev. comprises the
deviation component of the calibration Cal.dev. and that of the
measurement Meas.dev. as follows:
MC.dev. = (Cal.dev.) 2 + (Meas.dev.) 2
Cal.dev. display only
Deviation due to calibration (variable ML:)
Deviation of the mass concentration ρ
s
of the substance due to the
calibration (calibration curve or internal standard) (see also MC.dev. ).
The absolute value with numeric value and unit together with, in
brackets, the relative value in % is shown (for further details, see
section 6.9).
The deviation of the mass concentration
ρ
s
of the substance due to
the calibration can be used in formulae as ML: ( =
substance name) for further calculations. It should be noted that this
value is put out in such cases in the base unit g/L without prefix (see
section 5.6.4).
This field remains empty (
– ) if standard addition has been selected as
the calibration technique ( Technique = std.add. ) or no result has
been found.
Mass display only
Substance mass in measuring vessel (variable MS:)
Absolute mass of the selected substance in the measuring vessel with
numeric value and unit (g, mg,
µ g, etc.) determined with the aid of the
selected calibration ( std.add. , cal.crv. , int.std. ).
The absolute mass of the substance in the measuring vessel can be
used in formulae as
MS: ( = substance name) for
further calculations. It should be noted that this value is put out in
such cases in the base unit g without prefix (see section 5.6.4).
The relation between
Mass and Mass conc. is given by
Mass conc. = Mass / V0.sample
This field remains empty ( - ) if no calibration technique has been
selected ( Technique = none ) or no result has been found.
Add.mass display only
Standard addition mass (variable MA:)
Mass of the selected substance with numeric value and unit (g, mg,
µ g, etc.) added in every standard addition.
The standard addition mass can be used in formulae as MA:
( = substance name) for further calculations. It should be
noted that this value is put out in such cases in the base unit g without
prefix (see section 5.6.4).
This value can be used to asses whether the standard addition ratio
has been correctly selected (cf. remarks on
std.add. in section
5.6.3).
This field remains empty (
– ) if standard addition has not been se-
lected as the calibration technique ( Technique ≠≠ std.add. ).