Duct Flow Measurement

The grid lines which lay out the duct flow measurement points are traverses.

Duct flow measurement.

For duct sides less than 30 inches 5 traversal points must be taken along that side. One third toward the center. Note the air most affected by friction is seemingly over represented. The rough airflow measurements for different inches are.

An orifice meter connected to a large tank is attached to the engine intake manifold to make air flow measurements. For duct sides of 30 to 36 inches 6 points must be taken. In the uk cibse standard tm26 recommends duct cleaning if measured bacterial content is more than 29 colony forming units cfu per 10 cm 2. Twothirds toward the center.

Three measurements are taken per radius. Sealing leaks in air ducts reduces air leakage optimizes energy efficiency and controls the entry of. For duct sides greater than 36 inches 7 points must be taken. Air pressure combined with air duct leakage can lead to a loss of energy in a hvac system.

Verabar a new idea in duct air flow measurement the veris verabar is designed to be the most reliable accurate and repeatable method of measuring volumetric or mass airflow in round and rectangular ducts. Duct mounted airflow measurement station is easy to install and utilizes an airflow averaging element. The fuel flow rate is measured with a coriolis mass flow meter. This meter uses the coriolis effect to measure the amount of fuel moving through the element.

25 cfm for 1 5 inches 3 8 cm 35 cfm for 2 inches 5 1 cm 48 cfm for 2 5 inches 6 4 cm. These measurements are related by the material s density. The density of a liquid is almost independent of conditions. The log linear method provides high accuracy 3 in flow totalization by measuring air flow closest the edges of the duct space preferentially.

Both gas and liquid flow can be measured in physical quantities of kind volumetric or mass flow rates with units such as liters per second or kilograms per second respectively. A total of eighteen readings accurately describes the air flow velocity. It will depend on the shape of the duct itself. The number of data points to be taken along each side of the duct depends on the width of that side of the duct.

Three traverses diameters evenly spaced at 60 create six pieces of pie in a round duct. Contamination is classified as low below 10 cfu cm 2 medium at up to 20 cfu cm 2 and high when measured above 20 cfu cm 2. Series pafs 1000 ideal for sensing fan flow rates averaging flow sensor is ideal for sensing differential pressure in the inlet section of variable air volume terminal units and fan terminal units.