Flow Meter Calibration system

Flowmeter calibration can be divided into four sections, namely level, liquid, gas & mobile flow calibration meters.

Level calibrations use Electrical / Electronic and Pneumatic Consoles are housed in a sleek Panel / Test Bench Rack, designed ergonomically; a stand-alone Hydro (Water) Intensifier Unit caters to Pressure Tests. With Built-in Intelligent Software (with the facility of Retrieving / Recording / Interpreting & Displaying the Readings / Values received from various Test and Standard Instruments in easily understandable/user-friendly format) is provided for generation of Calibration Certificate / Chart / Report.

Types of level Instruments –best Suited for	Tests that can be performed
Float type level instruments	Linearity
Displacer	Dead band
Radar	Sensitivity & Resolution
Capacitance	Pressure test
Ultrasonic	Hysteresis
Magnetic	Repeatability
Built-in & External chamber	Functional

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Nagmanflow’s Water meter calibration system is most suited for verifying / Calibrating – Domestic Water Meters of Sizes from DN 15 to DN 50 and Bulk/Industrial meters of Sizes above DN 50 up to DN 300.

Complete Integrated System with Pumps (with VFD), Rotameters or Flow meters / Manual or Automatic Throttles for Flow Rate Control. Reservoir, Test Bed with Quick Clamping Systems / Spacers & Blanks and Electric Control Console / Calibration Software.

Boon to Water Boards / Jal Nigam / Municipal Corporations / OEMs & Calibration Labs

Best Suited for Single JET, Multi Jet, Electromagnetic and Ultrasonic water meters covering AMI / AMR features.

Nagmans gas Calibration Standard’ of the Test Bench is “Bell Prover”, which is considered a Primary (Calibration) Standard to Test & Calibrate Domestic Gas Meters (& Gas Meters used in Hotels/Restaurants etc.). The device is ideal for OEMs, Calibration Laboratories & Calibration Service Providers.

The Test Bench, with 2 Sizes of Bell Prover (20L & 100L)will effectively cover Very Low (Qmin – typically 0.016 m3/h (0.27 LPM)) to Maximum (Qmax – 6 m3/h (100 LPM)) Flow Rates. Available Accuracies : 0.2% & 0.5% F.S.

Upto 4 Gas Meters can be connected (inserted) during a campaign. Facility provided for continuously monitoring Differential Pressures (DP) across each Meter as well as upstream & downstream Line Pressures & Line Temperatures. Line Pressures are regulated typically around 500Pa.

Nagman’s BELL PROVER

Bell prover helps the gas flow meter test bench to sample and calibrate the gas flow. It can test rota meter, gas meter, and other forms of a gas flow meter. The bell prover can move up and down automatically and the gas-output valve can switch automatically.

The Bell prover and liquid cell form a sealed space of variable volume. When the Bell moves down into the sealed liquid, through pressure compensation mechanism, the internal gas pressure does not vary along with the changed depth of the sealed liquid. Meanwhile, the gas in the Bell is exhausted to the flow meters through a connect pipe. The exhausted gas volume will be detected compared with the cumulative in the meters.

Sizes	G 1.6 to 6
Working pressure	1 KPa to 5 KPa
Flow range	0.2 m3 / hr. to 120 M3/hr
Accuracy	0.2 to 0.2%

Nagmanflow’s Sonic Nozzle

A “sonic nozzle” (also known as “Critical Flow Venturi” or “Critical Flow Nozzle”) is a flow meter that can be used as a calibration standard for gas flow meters or any flow measurement device. By design, sonic nozzles are a constant volumetric flow meter.

The nozzles are designed and manufactured to the ISO standard and as such the gas is accelerated along the Bell Mouth converging section and then is expanded in a conical diverging section, which is designed for pressure recovery. In the throat or minimum area point of the Sonic Nozzle, the gas velocity becomes equal to the speed of sound. At this point, gas velocity and density are maximized, and the mass flow rate is a function of the inlet pressure, inlet temperature, and the type of gas. So, you only need to measure the inlet pressure and temperature to determine the flow rate.