Manual

<2. About the EJX Multivariable Transmitter>

2-7

IM 01C25R01-01E

(6) Downloading ow parameter to a transmitter

Input Kfactor, Tb, SPb and TempK 1 to the

transmitter using either a Communication tool

or FlowNavigator.

Use the unit of “Kg/m

/degC” for TempK1

IMPORTANT

If either the setting of ow unit or differential

pressure unit is changed, Kfactor and Nc must

be recalculated.

Example 1: Calculation of Nc

(1) When ow unit is changed.

Nc= (Kg/s) /(Mass Flow unit in use)

Table 2.6 Example of Calculated Nc by Flow Unit

Flow unit Calculation of Nc Nc

kg/s (kg/s) / (kg/s) = (1kg/1s) / (1kg/1s) 1

kg/h (kg/s) / (kg/h) = (1kg/1s) / (1kg/3600s) 3600

lb/s (kg/s) / (lb/s) = (1kg/1s) / (0.4535924kg/1s) 2.204623

lb/h (kg/s) / (lb/h) = (1kg/1s) / (0.4535924kg/3600s) 7936.648

(2) When differential pressure unit is changed.

Nc = (Differential pressure unit)/(Pa)

Table 2.7 Example of Calculated Nc by Differential Pressure Unit

T0202.ai

∆p unit

inH2O@68degF / Pa = 248.6406Pa / 1Pa

Calculation of Nc

248.6406 = 15.76834

kPa

inH2O@68degF

(Pa) / (Pa) = (1Pa) / (1Pa)

kPa/Pa = 1000Pa / 1Pa

1 = 1

1000 = 31.62278

(3) When both ow unit and differential pressure unit are changed.

Nc =(Kg/s)/(Mass Flow unit of use) × (Differential pressure unit of use)/(Pa)

Example 2: Calculation of Kfactor

Qm unit = kg/s, Differential pressure unit = kPa

Kfactor = /4 × Nc × C/ 1− β

× ε × d

× 2×ρb×1/K

= 0.7853982 × 31.62278 × 0.6043 / 1−0.1296 × 0.984 × 0.03162

× 2×1.250380×1/1

= 0.02502868

0.02503