Speed/Flow (Root Function); None; Hold Function - PCE Health and Fitness PCE-PDA A100L Instructions For Use Manual

3.4.4. SPEED/FLOW (Root function)

The PCE-PDA gauge carries out the calculation of the flow speed on the basis of measuring
the differential pressure on the plate. These plates can for example be Pitot´s tube, Prandtl´s
tube or another throttling organ. The plate properties are represented by the K constant and
a power constant x. The K constant has the default value 1 and can gain values 0 – 9.999.
The x constant has the default value ½ (0.5000 – square root) and can be adjusted to the
value 0,0001 to 0.9999. It is also necessary to set the density of the measured medium ρ(ró)
(default air 1.29 kg/m
This relation is valid for the speed calculation:
Where: v=flow speed, k=plate constant, dP= measured differential pressure, ρ=measured
medium density in kg/m
For the flow calculation:
Where: Q=flow, v= measured flow speed, S=section in m

3.4.5. NONE

With the choice None function, the secondary display (10) remains blank.

3.4.6. HOLD FUNCTION

The HOLD function "holds" the actual measured pressure value on the main display (6). It is
active after pressing the navigating button (16) HOLD >. After it is released, the main display
shows values according to the actual adjustment of the PCE-PDA.
3
) and the section of the measured pipe S.

2 dP
   
v k


3
, x=power constant
 
Q v
Instructions for use PCE-PDA
Picture 9
x

 
 
m s

 
3
S m s
2
12