Metrohm 757 VA Computrace - Manual (Page 5)

1.1 Instrument description
757 VA Computrace – Hardware
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1 Introduction
1.1 Instrument description
757 VA Computrace is a PC-controlled system for voltammetry, which consists of
the following parts:
1.757.0010 VA Computrace Stand with accessories
6.5326.000 VA Computrace Interface
6.2135.010 Connecting Cable
6.6032.100 VA Computrace Software 2.0
For a detailed description of the PC software «VA Computrace 2.0» see the 757
Software Manual.
This 757 Hardware Manual describes the installation and maintenance of the 757
VA Computrace Stand and its accessories. The central element of this Stand is the
multi-mode electrode (MME), which combines the dropping mercury electrode
(DME/SMDE) and the stationary hanging mercury drop electrode (HMDE) in a sin-
gle construction. The rotating disk electrode (RDE) can also be used in the stand.
The parameters necessary for the VA measurement are sent from the PC to the VA
Computrace Interface via USB connection. The data acquisition at the 757 VA
Computrace Stand is started and controlled by the VA Computrace Interface, which
receives and stores the measurement data. At the end of the determination, the re-
corded data are sent back to the PC where they are evaluated and saved in a de-
termination file.
Operation of the 757 VA Computrace Stand follows the potentiostatic 3-electrode
principle in which the voltage of the working electrode is controlled by means of a
virtually currentless reference electrode to the preset desired value and the current
flows across a separate auxiliary electrode.