Filter
Top Products
Overview
The HART variables are a set of four variables predefined for HART use. The HART variables
include the Primary Variable (PV), Secondary Variable (SV), Tertiary Variable (TV), and
Quaternary Variable (QV). You can assign specific process variables to the HART variables,
and then use standard HART methods to read or broadcast the assigned process data.
Tip
The Tertiary Variable and Quaternary Variable are also called the Third Variable (TV) and Fourth
Variable (FV).
Restriction
One some devices, the PV is fixed to a specific process variable and cannot be changed.
Options for HART variables
Options for HART variablesTable 6-7:
Process variable
Primary
Variable
(PV)
Secondary
Variable
(SV)
Third Varia-
ble (TV)
Fourth Var-
iable (QV )
Standard
Line Density ✓ ✓ ✓ ✓
Line Temperature ✓ ✓ ✓ ✓
Line Temperature (External) ✓ ✓ ✓ ✓
Line Pressure (External) ✓ ✓ ✓ ✓
Drive Gain ✓ ✓ ✓ ✓
Volume Flow Rate (External) ✓ ✓ ✓ ✓
Mass Flow Rate (Calculated) ✓ ✓ ✓ ✓
User-Defined Calculation Output ✓ ✓ ✓ ✓
Board Temperature ✓ ✓
Input Voltage ✓ ✓
Viscosity measurement
Dynamic Viscosity ✓ ✓ ✓ ✓
Kinematic Viscosity ✓ ✓ ✓ ✓
Referred Viscosity ✓ ✓ ✓ ✓
Secondary Referred Viscosity ✓ ✓ ✓ ✓
Quality Factor (Q Factor)
(1)
✓ ✓
API referral
Referred Density (API) ✓ ✓ ✓ ✓
Integrate the meter with the control system
110 Micro Motion
®
Fork Viscosity Meters (FVM)