Filter
Top Products
Installation and Configuration Manual 63
Calculated Parameters
Calculated Parameters Modbus CommunicationsSafety CertificationFactory Default Settings
A correlation equation has been established for from the available compressibility data; such as,
log
e
C = -1.62080 + 0.00021592t + 0.87096 x 10
6
(ρ
15
)
-2
+ 4.2092t x 10
3
(ρ
15
)
-2
per bar
where
• β = C x 10
4
Bar
• t = Temperature in deg C
• ρ = ρ
15
/ 1000 = oil density at 15 °C (kg/litre)
B.3 Kinematic viscosity
Kinematic viscosity is defined as:
where
• ν = kinematic viscosity (cSt)
• η = dynamic viscosity (cP)
• ρ = density (Kg/m
3
)
B.4 Base kinematic viscosity referral using ASTM D341
Base kinematic viscosity is the viscosity of the fluid at a specified base (or referral) temperature
which is different to the line (i.e., the actual) temperature of the fluid. Base viscosity can be
calculated using the kinematic–viscosity–temperature charts covered by the ASTM D341 standard.
The base kinematic viscosity of a petroleum oil or liquid hydrocarbon can be determined at any
temperature within a limited range, if the kinematic viscosities at two temperatures are known.
The ASTM D341 standard charts use the following equation:
where
• ν = kinematic viscosity (cSt)
•
Τ
= temperature (deg K)
• A and B are constants for the liquid (defined by the ASTM tables)
The meter can be programmed with up to four ASTM curves that allow viscosity referral over a wide
operating range. A ratio technique is employed when operating between the ASTM curves.
B.5 Ignition quality
The ignition index (C
II) is defined as:
ρ
η
ν
=
ν 0.7+()loglog A B Tlog–=
CII =
()()
7.0vLOGLOG*708.23*254565.0t*1038.0795.270
15
++ρ−+