Although the Digi-Flo is designed to withstand outdoor conditions, a cool, dry location where the unit can be easily serviced is recommended.

• The Digi-Flo can be mounted on horizontal or vertical runs of pipe. Mounting at the twelve o'clock position on horizontal pipe is recommended. Mounting anywhere around the diameter of vertical pipe is acceptable, however, the pipe must be completely full of water at all times. Back pressure is essential on downward flows.

• The Digi-Flo accuracy is affected by disturbances such as pumps, elbows, tees, valves in the flow stream. Install the meter in a straight run of pipe as far as possible from any disturbances. The distance required for accuracy will depend on the type of disturbance. See illustrations and table below.

• The pipe must be completely full at all times. Air bubbles or air pockets in the flow stream will adversely affect the reading. A small amount of back pressure is recommended in horizontal runs of pipe.

• The Digi-Flo accuracy is based on steady, undisturbed flow with a fully developed turbulent flow profile. Pulsating, swirling and other disruptions in the flow stream will effect the meter’s accuracy.

• The F-1000 is factory calibrated to ± 2% and the F-2000 is calibrated to ± 1% of full scale linearity. Accuracy is based on laboratory testing of nominal pipe dimensions. Your actual accuracy will vary based on your actual pipe I.D. And other installation factors.

• There are two basic types of flow profiles; turbulent and laminar. Turbulent flow exists when the speed of the fluid flowing in the pipe is nearly constant across the entire width of the pipe. This is typical of low viscosity fluids; like water, flowing at high velocity. Laminar flow exists when the speed of the fluid flowing in the center of the pipe is greater than the speed of the fluid at the outer edge near the pipe wall. This is typical of high viscosity fluids flowing at low velocity. Because the Digi-Flo is measuring the fluid near the pipe wall only (especially in larger pipe sizes), a constant flow velocity across the flow stream is required.

To determine which type of flow exists in your installation, the following is required:

Flow rate of the fluid in GPM - Q
Specific gravity of the fluid - G
Pipe inside diameter in inches - D
Fluid viscosity in Centipoise - V

Use the following equation to determine the REYNOLDS NUMBER:

REYNOLDS NUMBER  =  (3160 x Q x G)  /  (D x V)

Flow conditions with a Reynolds Number greater than 4000 is fully developed turbulent flow. A Reynolds Number less than 2000 is laminar flow. The Digi-Flo requires a Reynolds number greater than 4000 to maintain accuracy.