Metrohm 743 Rancimat - Manual (Page 9)

￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭ 1 Introduction
743 Rancimat ￭￭￭￭￭￭￭￭ 1
1 Introduction
1.1 Instrument description
The 743 Rancimat is a PC-controlled measuring device for determining the
oxidation stability of samples containing oil and fat.
It is equipped with two heating blocks each with 4 measuring positions
(channels). Every block can be heated individually, i.e. 4 samples can each
be measured at 2 different temperatures or 8 samples at the same tem-
perature. The measurements at the individual measuring positions can be
started individually for this.
Operation of the 743 Rancimat is realized completely via a PC connected
to the RS-232 interface using the control and evaluation program 743
Rancimat. Up to 4 instruments can be connected to each PC, hence
allowing a maximum of 32 samples to be analyzed. The evaluation algo-
rithm of the PC program determines the break point of the Rancimat
curve fully automatically and hence the induction time. Besides the induc-
tion time, the so-called stability time, i.e. the time duration until attain-
ing a defined conductivity change, can also be determined. In the case of
conductivity changes (stages) which do not have anything to do with the
autoxidation, the evaluation can be interrupted for definite time intervals.
The results determined can be processed further by computer. In particu-
lar, the induction times can be converted to the default temperatures of
the corresponding standards.
Each Rancimat curve can also be evaluated manually. A PC-supported
tangential method is available for this, in which you can position the tan-
gents anywhere on your curves. This makes evaluations possible in
extreme cases as well.
The results of the determinations are saved in a database together with
all methods and determination data. Determinations can be searched for,
sorted, filtered, exported and printed in the program part for the results
display. Besides the graphic display of single and multiple curves, recalcu-
lation with altered parameters and extrapolation of the results to a defi-
nite temperature is also possible.
GLP (Good Laboratory Practice) and instrument validation are becoming
increasingly important. The 743 Rancimat enables GLP tests for tempera-
ture, conductivity and gas flow measurement. You determine whether
and which tests have to be carried out. You can also specify the time
interval between the tests as well as the requirements regarding accuracy.
If the GLP function has been selected, each result report will receive a
comment stating whether the GLP tests have been fulfilled. Metrohm