Converting CFM on an Anemometer help? 4.5 inch orifice on vacuum

In summary, the speaker is asking for help in converting the reading from their anemometer to accurately measure the volume per minute of a 4.5 inch orifice. They provide a link to the specific anemometer they bought and mention that they need to calculate the area and velocity in order to get the accurate measurement. They also suggest dividing the velocity by 10 if the anemometer reads in feet per minute.
  • #1
Bonedrycarpet
1
0
I have an anemometer that I bought that does not have the ability to put in the ID of the orifice I am trying to measure. In this case it is a 4.5 inch orifice-stays the same for me 95 percent of the time. Does anyone know how I convert the reading manually so that I can get an accurate reading on my anemometer?

Below is the link to the meter I bought on ebay-it is a cps avm 03.

http://rover.ebay.com/rover/0/e11051.m43.l1123/7?euid=88c820308fc348969bfbebe2f4e7378a&loc=http%3A%2F%2Fcgi.ebay.com%2Fws%2FeBayISAPI.dll%3FViewItem%26item%3D110905158318%26ssPageName%3DADME%3AX%3ARTQ%3AUS%3A1123

Thank you!:smile:
 
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  • #2
I think you are asking how to calculate the volume per min given the diameter and velocity?

= area * velocity.

If you want it in cubic feet per min then the area needs to be in square feet and the velocity in feet per min.

The area is..

= ∏r2/144
= 3.14 * (4.5/2)2/144
= 0.11 square feet

So if the velocity is say 4 feet per second then the cfm is

= 0.11 * 4 * 60

If the anemometer reads in feet per min then you don't need to multiply by 60.

(Edit: I don't know how accurate you need the result but if the annemometer reads velocity in feet per min then it might be sufficient to just divide that by 10 and call it cfm)

All this assumes the anemometer doesn't block and reduce the airflow significantly.
 

FAQ: Converting CFM on an Anemometer help? 4.5 inch orifice on vacuum

What is CFM on an Anemometer?

CFM stands for cubic feet per minute and is a measurement of the volume of air that is flowing through a specific area in one minute. In the context of an anemometer, it is used to measure the airflow velocity.

How do I convert CFM to other units on an Anemometer?

To convert CFM to other units on an anemometer, you will need to know the specific conversion factor for the unit you want to convert to. For example, to convert CFM to cubic meters per second, you would multiply the CFM value by 0.000471947.

What is the purpose of a 4.5 inch orifice on an Anemometer?

The 4.5 inch orifice on an anemometer is used to measure the velocity of the airflow. It is the standard size for orifices in anemometers and allows for accurate measurements of air velocity.

Why is vacuum used in conjunction with an Anemometer?

Vacuum is used in conjunction with anemometers to create a pressure differential and measure the velocity of air flow. This is because changes in air pressure are directly related to changes in air velocity.

How can I ensure accurate readings when converting CFM on an Anemometer?

To ensure accurate readings when converting CFM on an anemometer, it is important to calibrate the device regularly and follow proper measurement techniques. This includes ensuring a stable and consistent air flow, positioning the anemometer correctly, and using the correct conversion factors.

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