Eldridge Flow Measurement

Eldridge Flow Measurement was founded in June 1988 in Marina, California, by President and CEO Mark Eldridge. Today, with over 30 years of experience in the industry.

About Eldridge Products Inc

EPI is the world’s premier manufacture of thermal mass flow meters, switches, and metering software. With an ever-growing team of the industry’s best engineers, designers, and support specialists, EPI offers clients the reliable and accurate products they’d expect from a global leader coupled with the personal attention and dedicated service they’d expect from a family business.

At EPI, we understand the challenges our customers face every day when measuring thermal mass flows of all types. We also understand the opportunities that accurate measurement represents to both the bottom line and to the environment. With those challenges and opportunities always at the top of our minds, we’ve spent decades developing a full line of thermal mass flow metering products that are unparalleled in their accuracy, their ease of use, and their reliability. EPI thermal mass flow meters take the headache and complexity out of repeatable, accurate flow measurement and eliminate the need to worry about expensive system downtime.

Equally as important to us as the quality of our products is the quality of our people and the relationships we build with our customers – customers who know that, with EPI, they aren’t just buying hardware or software; they’re gaining a true partner. At the core of everything we do is the understanding that our customers’ success and our own are inextricably linked, and it’s that knowledge that drives our unwavering commitment to offering the best thermal mass flow meters and the best service the industry has to offer.

Technical Information About EPI

Flow Meter Considerations for Flow Conditions

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 Temperature

This 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.


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 or 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, IP66. For use in hazardous area locations (options): ACEX or DCEX.
  • Master-Touch™ MPNH Series
    • For use in Ordinary (Non-Hazardous) area locations: Type 4X, IP66.
  • ValuMass™ Series 400 and 500
    • CE Mark

Configurations for Inline, Insertion, Remote, & Integral Style Meters

Inline Style Mounting

Eldridge Products Inc
Inline Style Mounting

Thermal mass flow meters for inline style mounting include a flow section that is usually specified to match the user’s flow conduit and is then plumbed directly into the process line. This design has the sensing elements mounted directly in the flow section for exposure to the process gas. Our inline style thermal mass flow meters are available in sizes from 1/4″ pipe through 4″ pipe or tube, and are provided with a variety of options such as MNPT ends, tube end fittings, butt weld ends, flanged end configurations, etc. as required. Pipe sizes in excess of 4″ typically require insertion style thermal mass flow meters although EPI™ has manufactured inline style flow meters for pipes as large as 8″.

Insertion Style Mounting

Eldridge Products Inc
Insertion Style Mounting

Thermal mass flow meters for insertion style mounting include a sensor & probe assembly that is inserted into the process gas flow conduit to allow the process gas to flow across the flow sensing elements. Our insertion style flow meters are available with 1/2″, 3/4″, or 1″ OD probes. Tube fittings and ball valve retractor assemblies, with or without a mounting flange, are also available from the factory as options. The tube length must be specified upon ordering. Standard lengths range from a minimum of 6″ to a maximum of 36″. For other probe diameters and lengths, please consult the factory.

Integral Style Electronics

Eldridge Products Inc
Integral Style Electronics

Thermal mass flow meters with integral electronics have all of the electrical components and connections located within one enclosure. This enclosure may be rated for either hazardous environments MP Series or for ordinary, non-hazardous environments MPNH Series, as necessary. The enclosure is mounted directly to the inline flow section or to the insertion probe assembly at the point of measurement. The enclosure includes the all the electrical connections as well as the linearizing electronics and the display/keypad assembly.

Remote Style Electronics

Eldridge Products Inc
Remote Style Electronics

Thermal mass flow meters with remote electronics utilize two enclosures. The flow transmitter enclosure is mounted at the point of measurement — on the flow section or on the probe assembly. This enclosure may be rated for either hazardous environments or for ordinary, non-hazardous environments, as necessary. In our standard configuration, the second (remote) enclosure is usually placed in a readily accessible location rated for non-hazardous conditions.

Our optional ACEX (AC power) and DCEX (DC power) enclosures carry the same area classification as the corresponding flow transmitter enclosure. The remote enclosure includes the all the electrical connections as well as the linearizing electronics and the display/keypad assembly. Depending upon the application requirements, a two-, four- or six-wire, twisted-pair cable is required to carry the input power and flow signal between the two enclosures.

Industrial Applications for Meter


Uncompressed air and oxygen gas are used in a wide variety of commercial and industrial applications, covering everything from steel production to dehydrating fruit to renewing municipal water supplies. Uncompressed atmospheric air is chosen for many applications for obvious reasons – it’s plentiful and effectively free. Pure oxygen is more costly, but its chemical properties make it an important input in many industrial processes where.


Methane is a greenhouse gas that is emitted naturally from a number of sources, including wetlands, the oceans, the breakdown of organic materials like human and animal waste, wildfires, and more. Methane is also a key gas used in commercial and industrial applications. On average, it makes up 94% of the natural gas used to power industry and our homes, and it’s also key in everything from chemical production to advanced rocket fuels.

Flue Gas

Flue gas is produced anywhere a non-electric furnace or boiler is used to generate heat. That includes the furnaces and chimneys in many of our homes, but the source of the vast majority of flue gasses – and thus, the source of greatest concern – is industrial processes. The sheer volume of flue gas released into the atmosphere from factories and plants means that carefully monitoring it is crucial to maintaining the health of the environment and the people who.

Eldridge Products Inc Products

  1. EPI-HAZ: HAZ flow meters are certified for Hazardous Locations with an explosion-proof enclosure.
  2. EPI-GEN: GEN flow meters are certified for Ordinary/General Locations with an corrosion resistant, watertight enclosure.
  3. EPI-VAL: VAL flow meters use the same accurate sensor technology, but offer a lower-cost alternative for those who do not need advanced features.
  4. EPI-PURE: PURE thermal mass flow meters are specifically engineered for ultra high-purity applications.
  5. EPI-XT: EPI XT mass flow meters are designed to measure gas flow in extreme temperature environments.
  6. EPI-MULTIGEN: The EPI MULTI series flow meters are multi-point, which use multiple connected sensor assemblies connected to a remote control panel for metering large pipes/ducts.
  7. EPI-SWITCH: SWITCH flow switches are built with an explosion-proof rated enclosure and can be used to monitor gas flow accurately.

Source: epiflow.com

Read More Articles :

%d bloggers like this: