Our new 2-piece sensor is capable of measuring three properties of
viscous fluid flow described by Poiseuille's Equation :

**
Q = pr**^{4}(P1-P2)/(8h*l*)

When an oil sample is measured, three properties
are compared to the NIST traceable viscosity standards used to calibrate
the TriVisc. A proprietary mathematical calculation is performed
to determine the **
Confidence Factor**.
Physical phenomena which modify the flow characteristics will introduce errors
into the
viscosity calculation and lower the **
Confidence Factor**.

**(P1 - P2)** -
is the pressure difference induced by
gravity on one end and a vent on the other. Small
amounts of water boiling out of the sample, or
entrained gases escaping will effect this term.
Even a restriction in a valve or improper cleaning
will have an effect. The TriVisc looks for this to be constant throughout the
measurement phase.

**r**^{4}
is the
capillary tube radius.
Radius changes are raised the 4th power!
Soot and insoluble contamination on the capillary
wall will effect this constant. Temporary partial
blockages from debris will reduce the
cross sectional area effecting this term. The TriVisc will detect when the tube has become too
dirty to perform accurate measurements.

**Q** is
a the volumetric flow rate. Conventional
viscometers factor only this term into their
calculations. A
Start Sensor and a Stop Sensor are used to time how
long it takes to fill a bulb in the glass.
Using this term alone will make your measurements
prone to error.

The TriVisc uses all three flow
properties to calculate the **Confidence Factor**.