An AMCA Standard 210 double chamber is used to accurately measure air volume
and static pressure.
|
| Maximum static pressure: As
shown in the figure, when closing the nozzle, the pressure in
the A chamber will reach the maximum. This differential
pressure (Ps) between the air pressure and the pressure in the A chamber can be called
the maximum static pressure. |
| Maximum air flow: When opening
the nozzle and absorbing the air using the auxiliary blower to
make the static pressure zero (Ps = 0), the differential pressure (Pn) between A chamber and B chamber will reach the maximum. The air flow
obtained by applying the differential pressure (Pn) to the above equation can be called the maximum air flow. |
|
| Note : |
Fan performance is calculated using the data obtained from this equipment
according to the following formula:
|
| The Equation : |
Air flow |
 |
|
|
|
|
|
|
| C |
: |
Coefficient of nozzle air flow |
| D |
: |
Diameter of nozzle (m) |
| r |
: |
Air density |
 |
|
|
|
| t |
: |
Temperature (oC) |
| P |
: |
Air pressure (hPa) |
| Pn |
: |
Differential pressure of air flow (Pa) |
| g |
: |
9.8m/s2 |
|
Use the tables of multipliers below to convert between units.
 Airflow |
| CFM |
m3/min |
m3/hr |
L/sec |
| 1 |
0.028 |
1.7 |
0.47 |
| 35.3 |
1 |
60 |
16.7 |
| 0.59 |
0.017 |
1 |
0.28 |
| 2.12 |
0.06 |
3.6 |
1 |
|
Example: To convert from CFM to m3/hr multiply by 1.7.
|
Static Pressure |
| in H2O |
mm H2O |
Pa |
| 1 |
25.4 |
249 |
| 0.039 |
1 |
9.81 |
| 0.004 |
0.1 |
1 |
|
| Example:
To convert from Pa to in.H2O multiply by 0.004. |
|
|
