Xylem SI Analytics AVS 370 Manual De Instrucciones página 31

1.5
Functioning of the device
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The AVS 370 is used to perform flow-time measurements in capillary viscometers in combination with the
WinVisco software. It is operated via a Personal Computer. The WinVisco software can be used to display the
time readings. The results of a measurement series can be stored on the PC.
When using up to four different modular ViscoPump III units, the AVS
used for meniscus sensing.
The available capillary viscometers enable viscosity measurements 0.35 of approx. 5,000 mm
carried out at a measuring temperature of approx. 20 ... 25 °C.
Connecting TC viscometers to the ViscoPump III VZ 85622 module will also enable the measurement of black
and opaque liquids. As an alternative option it is possible to use viscometers in combination with the light-
optical ViscoPump III VZ 8561 module viscometers for meniscus sensing with the measurement stand, e.g.
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the AVS /S.
Prior to the measurement as such, the liquid to be measured is sucked upwards inside the capillary
viscometer though two measurement planes (N2 and N1) which are designed as light barriers or thermistor
sensors, depending on the viscometer type (see  Fig.2 and Fig. 3).
The pumping pressure is controlled automatically by the AVS
When using Ubbelohde viscometer, the design of the program ensures that the suspended spherical level will
form prior to the start of the measurement.
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The AVS 370 is equipped with two RS-232-C interfaces for data transfer; these interfaces also allow several
units to be chained.
The number of devices which can be connected to the computer depends on the software being used
(presently it is limited to two AVS
A maximum of 2 AVS
connected to one PC.
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The AVS 370 can also be operated with ViscoPump II - modules, the older ViscoPump generation. A mixed
configuration with ViscoPump II und III - modules is also possible. In the case of a mixed configuration, please
note: The ViscoPump II - modules may only be used in the first measuring positions, i.e. in the slots to
the left of the ViscoPump III - modules (see  Fig. 1). If the ViscoPump modules are placed in the
wrong order, transmission errors will occur during RS communication!
Fig. 1 Measuring positions ViscoPump II and III – Module in the AVS
1.6 Capillary viscometry
Capillary viscometry is the most accurate method for the determination of the viscosity of liquids with a
Newtonian flowing behaviour. The measurement as such consists in a time measurement. The time measured
is that which a specific quantity of liquid requires to pass through a capillary having a defined width and length.
Conventionally, this process is watched with the human eye, and the flow time is measured manually using a
stop watch.
In the case of the AVS
is captured on the measurement planes, either in an optoelectronic manner by means of light barriers, or else
on a thermo-resistivity basis by thermistors.
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370, with 4 ViscoPump III modules each).
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370 viscosity measuring devices, each with up to 4 ViscoPump III module, can be
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370, as with all viscometry measuring devices from SI Analytics
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370 can be upgraded in two ways to be
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370 via the ViscoPump III module.
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370
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/s (cSt) to be
2
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, the liquid meniscus