Micro Motion 7827 Digital Viscosity Meter
3
Typical applications
•
Heavy fuel oil (HFO) heater control to burners
and engines
•
Lube oil viscosity control
•
Interface detection in multi-product pipelines
•
Mass flow, when used in conjunction with a
volumetric flow meter
•
Product mixing and blending
Typical industries
•
Oil and petrochemical
•
Refining
•
Power
•
Heavy Fuel Oil (HFO) blending and bunkering
Principle of operation
The 7827 digital viscosity meter uses a vibrating
fork technology to measure density and viscosity. As
the liquid density changes, it affects the vibrating
mass of the meter. The change in vibrating mass
then affects the resonant frequency. Viscosity is a
function of the bandwidth, which is an indication of
the damping associated with the liquid.
The following figure illustrates how the 7827 meter
with a 7950/7951 signal converter uses the
resonant frequencies at point A (the lower
–3 db point) and at point B (the upper –3 db point)
to digitally calculate the density, bandwidth and
quality factor. These measurements then give
digitally determined values of fluid density and
viscosity.
Product 1
Product 2
Response
amplitude
Frequency (Hz)
Product 1 – Low Viscosity
Product 2 – High Viscosity
Bandwidth = Point B – Point A
Resonant Frequency = (Point A + Point B) / 2
Quality Factor = Resonant Frequency / Bandwidth
