Alnor HM680, Owner'S Manual, Page: 29 / 40

Chapter 6. Calculations Menu 23
Flow2
The desired system flow rate.
Output
The calculated required impeller diameter ( Diam2 ) to achieve the desired flow will automatically
update as the input parameters are changed. Using the ▲ and ▼ keys to scroll, and the ◄ and ►
keys to change the selected field, the unit of measure for impeller diameter may be adjusted.
Available units for impeller diameter are: in, and mm.
Pump Law Delta P
This Calculations Menu option allows for determination of required pump pressure drop. The calculation
is based upon the following affinity law: Pump pressure drop varies as the square of flow.
Figure 12: Pump Law Delta P Screen
Inputs
The following inputs are necessary for calculating the required pump pressure drop. Use the ▲ and
▼ keys to select the parameter to be updated, and the ◄ and ► keys to change the value of the
highlighted field. Units for the inputs are driven by what was last set in the Pressure and Flow
Measurement screens.
Flow1
The actual system flow rate.
dP1
The actual pump pressure drop.
Flow2
The desired system flow rate.
Output
The calculated required pump pressure drop ( dP2 ) to achieve the desired flow will automatically
update as the input parameters are changed. The units for pump pressure drop are driven by what was
last set in the Pressure and Flow Measurement screens.
Actual Flow
Actual Differential
Pressure
Desired Flow
Battery Status or
Power Input Type
Required
Differential
Pressure