Description and Specification for Lab Tenders
Capillary Tube Viscosimeter.
Capillary Tube Viscosimeter
The apparatus allows Poiseuille flows to
be investigated and enables precise measurements to be made of the
dynamic viscosities of liquids maintained at constant temperature, using
the readings of a single pressure and a recorded time interval.
The liquid whose flow characteristics are to be investigated is placed
in a removable thermostatically controlled vessel which may be
pressurised. The vessel supplies a capillary tube which is also
thermostatically controlled and interchangeable. The level of
pressurisation of the vessel and the temperature of the liquid can be
continuously varied as required ; the liquid is continuously stirred to
ensure that its temperature is uniform.
Teaching objectives
From the measurement of flow rate and of
loss of head along the capillary tube, the following may be investigated
using the viscometer :
Poiseuille flow of a liquid of known viscosity.
Measurement of the dynamic viscosity of a liquid and its variation with temperature.
Shear stresses in viscous liquids and friction forces in laminar flow in tubes.
Precise determination of the diameter of a capillary tube.
Technical specifications
The following instrumentation is provided with the apparatus :
A mercury manometer.
A thermometer.
A stopwatch for flow rate determination with a measuring cylinder.
A thermostatically controlled vessel.
A magnetic stirrer.
Capillary tube diameters : 0.2 and 0.4 mm.
Temperature range : ambient to 80°C to 0.5°C.
Pressure range : 0 – 100 cm Hg.
Dimensions : 37 x 65 x 40 cm high (without manometer) or 120 cm high (with manometer).
Net weight : 20 kg
Dimensions and weight
370 x 650 x 1200 mm
Net weight : 20 kg
Essential requirements
Electricity : 220 V, 50 Hz (Other on request).
Compressed air : 1 bar minimum