Connection Of Vz 7215 Absorption Traps; Connection Of The Vz 8552 Overflow Guard - Xylem SI Analytics AVS 470 Manual De Instrucciones

Connection of VZ 7215 absorption traps

2.3.3
In the "sucking" mode (vacuum), volatile components can enter the ViscoPump III module.
This is particularly problematic for corrosive solvents such as formic acid or dichloroacetic acid.
For these cases, a hose fitting "suctioning" VZ 8524 or VZ 8527 must be used!
(includes the absorption traps VZ 7215 and appropriate connecting hoses).
The absorption traps which prevent contaminations from penetrating into the pneumatic system of the
ViscoPump have to be inspected at regular intervals. If sodium lime is used as an absorption agent with
acidic solvents, the colour condition of the indicator is to be checked on a daily basis. As soon as this
condition has shifted to BLUE in the half of the absorber material, this is the very last moment to replace the
material for safety reasons.
If such a colour shift cannot be observed over an extended period of time, this may be
attributable to the fact that an acidic over-saturation of the material has caused a decolouration; this
may then appear as "normal", but it will definitely result in the destruction of the pneumatic system
after some time! This situation is explicitly excluded from the warranty coverage!
For non-corrosive solvents and oils, which contain volatile constituents, absorption traps with activated
carbon filling are available. When using activated carbon as an absorption agent (e.g. with solvents or used
mineral oils), a replacement should be made at intervals between 1 and 2 weeks; this depends on the load
factor which, in turn, is a function of the volatility of the materials.

Connection of the VZ 8552 overflow guard

2.3.4
We urgently recommend the connection of the VZ 8552 overflow guard (available as an option) for the
suction-mode operation of the ViscoPump III module. The connection of the VZ 8552 overflow guard
(capacitive sensor for the safety bottle) excludes over-pumping in suction mode (contamination of the
ViscoPump III module). The holder on the safety bottle accommodates the capacitive sensor.
When using the ViscoPump III module VZ 8561 (meniscus sensing by light barriers) the holder for the safety
bottle is to be attached to the measurement stand, e.g. the AVS
VZ 8562 (thermo-resistive measurement) the holder for the safety bottle is to be attached to the "viscometer
gallows" provided for the TC viscometer 5932.
Should any liquid be over-pumped into the safety bottle, the safety sensor will trigger a stop.
After emptying the safety bottle, the lateral LED on the capacitive sensor will go out. You may continue with
the measurements.
The electrical connection of the VZ 8552 overflow guard is made using DIN plugs on the front side of the
respective module of the ViscoPump III.
The sensitivity of the capacitive sensor has to be adapted to the medium being used.
To do so, please use the enclosed screw driver to adjust the lateral set screw in such a manner, that the
capacitive sensor in the built-in condition (i.e. without medium) are just close from responding
(i.e. the LED is on).
Viscosity depends on the temperature of the sample liquid. This means that the viscometers must always be
thermostated during the measurement. The measurement temperature has to be kept constant in order to
achieve an accurate result.
The transparent thermostats from SI Analytics
meet the requirements imposed on precision and constancy. The CT 72/2, CT 72/4 thermostats, for
instance, guarantee a temperature constancy of ± 0,02 K at a command temperature in the range of
10° to 40 °C, and a maximum fluctuation of the ambient temperature of ± 3 K.
As a rule of thumb, you may suppose that the temperature deviation, expressed in degrees, multiplied
with a factor of 10 will correspond to the deviation from the result in terms of %. This means that a deviation
of 0.05 °C corresponds to a possible error of 0.5 %.
In principle, two different transparent thermostats can be used on the AVS
®
/S. When using the ViscoPump III module
®
which were developed especially for capillary viscometry,
®
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