Preparation Of The Sample; Selection Of The Capillary; Cleaning The Viscometer; Measuring Operation - SI Analytics Micro Ostwald Mode D'emploi

Operating Instructions
1 Preparation of sample
Low-viscosity samples must be filtered through a SCHOTT glass filter porosity 2 to 4 (10 ... 100 lm) before
the measurement; high-viscosity samples, through a sieve with 0.3 mm mesh width (test sieve cloth 0.2,
DIN 4188). Samples, whose stock value in accordance with DIN 51 583 or pour point in accordance with
DIN 51 597 is not at least 30 °C lower than the test temperature, must be heated up to 50 °C before the
measurement.
2 Selection of capillary
The size of the capillary is to be selected in such a way that the uncertainty inherent in the Hagenbach
Correction does not exceed the allowable error for the time measurement (see table). For precision
measurements should, therefore, be chosen no flow times below 30 seconds. If necessary, a viscometer
with a smaller capillary is to be used.
3 Cleaning of viscometer
Before the first use, a cleaning with 15 % H
then be rinsed with a suitable solvent. It must be completely dry and dust-free.
4

Measuring operation

Exactly 2 ml of the sample liquid are filled with a pipette into the wider one of the viscometer tubes.
Hang viscometer with its stand Type No. 053 97 into a Glass-Panelled Thermostatic Bath from
SI Analytics GmbH.
To obtain the measuring accuracy of the viscometer, the constant temperature bath should maintain the set
temperature at a constant ± 0.01 °C (glass panelled thermostatic baths from SI Analytics GmbH).
Differences in temperature of only 0.1 °C may cause an error of as much as 0.6 % in mineral oils.
Measuring should take place only after an equilibration time of approx. 5 minutes.
The liquid is siphoned above the upper measuring mark M1. Then the flow time between the two timing
marks M1 and M2 is measured. The measuring operation can be repeated as often as necessary.
When using the viscometers in automated viscosity-measuring units (AVS®) by SI Analytics GmbH, the
viscosity is measured automatically.
Subjective measuring errors are eliminated, and the efflux times measured are available as a printed-out
document. According to the type and number of samples to be measured, an optimum measuring device
may be assembled which can be expanded to an automatic sampler. Rinsing and filling of viscometers and
measuring of sample with subsequent changing of sample is performed automatically. The timing marks
required for manual measuring are replaced by light barriers.
The accuracy obtained with the AVS® automated measuring system is greater since certain parameters
such as errors in reading, clock errors, etc. are eliminated.
7
Ostwald Micro
Viscometer
O and 15 % HCl is recommended. The viscometer should
2 2