Applications and Resources


Technical Information

Flow Meter Considerations

Flow meter considerations must be  understood for your flow conditions,. You must be sure to include certain parameters for the flow meter to be properly matched to your application. Please refer to the information below when requesting a quote, or you can submit our Application Data Sheet by email or fax. The category descriptions below will help you specify the proper flow meter:

  • Gas Composition Flow Meter Considerations for gas are simple if you are flowing air or a pure gas such as hydrogen, nitrogen, etc. Gas mixtures should be provided with each gas listed as a percent of the total, with the sum equal to 100%. Whenever possible, we calibrate your thermal mass flow meter with the actual gas. When this is not possible, we use a gas or gas mixture with closely equivalent heat transfer characteristics.
  • Full Scale Flow Rate Although you may not know your exact maximum flow rate (Full Scale), you must provide an estimate for the calibration. If the Full Scale is not known, it is best to over-estimate a flow. This information can be in units of mass/volume flow (SCFM, Lbs/Hr, NCMH, etc.) or velocity (SFPM, MPS, etc.).
  • Line Size Whether you are interested in an inline style or an insertion style thermal mass flow meter, we need to know your process line size. This may be expressed as the nominal pipe size and schedule (ANSI, DN, etc.) of round pipes or the outside dimensions and wall thickness (or gauge) of rectangular ducts, for example.
  • Process Gas Temperature and Line Pressure We calibrate your thermal mass flow meter under conditions as close to your process environment as possible, so it is important to know both the design and operational ranges of the gas temperature and the line pressure.
  • Electronics TemperatureThis refers to the ambient temperature of the environment surrounding the flow meter’s electronics. We can provide options for a wide range of conditions.
  • Input Power Requirements You must specify whether the thermal mass flow meter will be powered by 24 VDC, 115 VAC, 230 VAC. Consult factory for use with alternate power sources such as 12 VDC or solar panels.
  • Configuration EPI™ manufactures both Inline and Insertion style flow meters. We typically supply inline style flow meters for line sizes from 1/4″ to 4″ with a number of installation options such as MNPT ends, ANSI of DIN flanges, etc. Insertion style flow meters can be used in line sizes of 2″ or greater and can be mounted with ball valve retractor assemblies, compression fittings, pipe nipples, etc. EPI™ also manufactures flow meters with either Integral or Remote Style electronics. The integral configuration is generally less expensive, but the remote style allows easy access to the electronics even when the actual process line installation is in an otherwise inconvenient location.
  • Product Approvals EPI™ flow meters have been tested and approved by a number of certifying agencies. If your application requires an agency approval, please select from the list below:Master-Touch™ MP Series Flow Transmitter —
    For use in hazardous area locations by CSA/CUS (default except for EU), ATEX (default for EU), IECEx and KOSHA
    (customer must specify which approval is required)Master-Touch™ MP Series Remote Enclosure —
    For use in Ordinary (Non-Hazardous) area locations: Type 4X, IP66For use in hazardous area locations (optional): ACEX or DCEXMaster-Touch™ MPNH Series — For use in Ordinary (Non-Hazardous) area locations:
    Type 4X, IP66

    ValuMass™ Series 400 and 500 — CE Mark


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