kinematic viscosity

Principle: At a certain constant temperature, measure the time it takes for a certain volume of liquid to flow through a calibrated glass capillary viscometer under gravity. The product of the capillary constant of the viscometer and the flow time is the kinematic viscosity of the liquid being measured at that temperature. .

step

1. Adjust the viscometer to a vertical state, and use plumb lines to check the verticality of the capillary from two mutually perpendicular directions. Adjust the constant temperature bath to the specified temperature, and immerse the viscometer with the sample in the constant temperature bath to keep it warm for 10 to 15 minutes.

2. Use the rubber tube covered with the capillary viscometer tube to suck the sample into the expanded part with a suction ball, so that the sample liquid level is slightly higher than the upper mark line, and be careful not to allow the liquid in the capillary tube and the expanded part to generate bubbles.

3. Release the suction ball and record the time it takes for the liquid level to flow through the marking line.

4. The flow time recorded with a stopwatch should be measured repeatedly at least four times, and the difference between each flow time and its arithmetic mean should not exceed ±0.5% of the arithmetic mean.

Calculation: kinematic viscosity of the sample at temperature t
Where vt is the kinematic viscosity, m2/s; c is the viscometer constant, m/s; τt is the average flow time of the sample, s.

Take the arithmetic mean of the two repeated measurements as the kinematic viscosity of the sample.

Hydroxy-terminated polymethyl silicone oil (general type) IOTA 1203