Differential Pressure Flow Meter for difficult and varied flow conditions
Manas Microsystem is the leading manufacturers and supplier of Differential Pressure Flow Meters that can be used for measuring the flow of different gases including Bio Gas, LPG, Steam, Compressed air, and other gases. This flow meter is also called an Orifice Based Flow Meter.
These flow meters measure the volume flow in gases, liquids, and steam. They are effectively used in cases where high pressure, high temperature, or a large diameter play a role. Some of the main industries using these meters include chemical, oil, gas, and power industries.
This flow meter is best suited for applications where affordability, reliability, and ruggedness are of prime concern.
How does a differential pressure flow meter work, is one of the important questions that need to be addressed.
In a conventional system of measurement, the differential pressure generated by the orifice plate is measured by the DP transmitter. The output from the DP transmitter after square rooting is accepted as proportional to the flow rate. This assumption is true only when the density is constant. Unfortunately, the density of the compressible fluid is never constant. The density of compressible fluid changes with line pressure and line temperature, thus introducing errors in flow rate measurement.
Manas provides two versions, one is With Density Compensation and the other is Without Density Compensation.
How do you calculate flow rate with differential pressure?
For this, let us understand the working principle of the differential pressure flow meter.
As per BS 1042 / ISO: 5167 standards, the equation for mass flow when measured with orifice states:
Qm ∝√ρ. √ ∆P
Where,
Qm = mass flow rate.
ρ = instantaneous density.
∆P =differential pressure.
Thus, by measuring the line pressure and temperature and using relevant algorithms instantaneous density can be found. By knowing the correct density one can compute the accurate flow rate. The further operation of integration, square rooting is like an ordinary totalizer.
Features
- Size: 1 inch to 8 inch
- Type of flow element: Differential flow element
- Accuracy: ±2.5% of actual reading
- Typical turndown: 10:3
- Density compensation: Online monitoring and compensation of density
Communication protocol: MODBUS, RTU - Communication port: RS485, RS232 (optional)
Applications
- Engineering & Automation
- Textiles
- Chemical/pharmaceutical
- Food & Drugs
- Petrochemicals
- Fertilizers
- Steel/ Aluminum
- Sugar Factories/Distilleries

Product Details
Brand | manas microsystems |
---|---|
Mounting | Wall/Panel |
Max depth | 185mm |
Accuracy | ±0.25% of Full Scale |
Pressure unit | Kg/cm2 (g) or Bar (g) |
Steam pressure | 1 to 100 kg/cm2 (a) max |
Steam temperature | 100°C to 600°C max for superheated steam & 100°C to 309.6°C max for saturated steam |
Enclosure | Al Die-Cast/ABS plastic |
Power supply | 85 to 265V AC,50Hz,single phase |
Comm. Port | RS485 std., RS232 (Optional) |
Density Compensation | Online monitoring and compensation of density |
Dimensions WM Type | 310(L)x160(W)x105(D) |
Dimension PM Type | Bezel-144mm(H)x72mm(W)culout-138mm(H)x68mm(W) |

Product Details
Brand | manas microsystems |
---|---|
Mounting | Wall/Panel |
Max depth | 185mm |
Accuracy | ±0.25% of Full Scale |
Pressure unit | Kg/cm2 (g) or Bar (g) |
Steam pressure | 1 to 100 kg/cm2 (a) max |
Steam temperature | 100°C to 600°C max for superheated steam & 100°C to 309.6°C max for saturated steam |
Enclosure | Al Die-Cast/ABS plastic |
Power supply | 85 to 265V AC,50Hz,single phase |
Comm. Port | RS485 std., RS232 (Optional) |
Density Compensation | Online monitoring and compensation of density |
Dimensions WM Type | 310(L)x160(W)x105(D) |
Dimension PM Type | Bezel-144mm(H)x72mm(W)culout-138mm(H)x68mm(W) |

Product Details
Orifice flow meter consists of three sections Inlet Section, Orifice Plate, Outlet Section.
Inlet Section: It is an inlet pipe connection extended straight and part of the same diameter for an end connection that serves to the incoming flow of fluid, steam and gas, and where we measure the inlet pressure.
Orifice Plate: An Orifice Plate is positioned in the middle of the Inlet and Outlet Sections to form a pressure dip and hence do the flow measurement.
Outlet Section: Like the inlet section it is an extended straight segment part of the same bore as that of the outlet pipe for an end connection for an outgoing flow of fluid or gas where we measure the pressure of the media at discharge.
The material of construction: The Orifice plates in the Orifice meter, in general, are made up of stainless steel of varying grades like SS 304, 316.
Orifice flow meter size and shapes: Orifice flow meters are constructed in various forms depending on their application-specific requirement i.e., shape, size, and location of holes on the Orifice Plate.