Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Gas density measurement

Gas density measurement

Gas density measurement


Is there a way to measure/infer gas density (say in kg/m3 unit) using an orifice type of instrument / flowmeter (that is, based on Delta P measurement) ?

Example: If I have a gas line that is equipped with pressure, temperature instruments and a flow element device (orifice), is there a way to obtain gas density from these only three physical devices and information ?


RE: Gas density measurement

Not possible I think. You still need gas composition to derive z from a simulator / with manual calcs. Else use an inline gas densitometer, especially if gas composition is expected to vary. If gas composition is fixed, there are many equations that can be used (Redlich Kwong, Virial, BWRS, SRK etc). Gas densitometers are notorious for producing erroneous results, which is why many operators prefer to use a online Welker gas sampler, then send on to a lab based GC to get the composition.

RE: Gas density measurement

Thanks for the info.

What about ultrasonic flow meter ?

RE: Gas density measurement

Ultrasonic and coriolis meters can output gas density also.

RE: Gas density measurement

I have an additional question..

Is it possible to measure gas volumetric flowrate (Am3/h) using a flow element (orifice plate) instrument when the gas molecular weight / composition is unknow? Let us consider there are pressure and temperature transmitters installed on the gas line under consideration (with purpose of doing flow compensation).

RE: Gas density measurement

Flow derivation with dp measurement across an FE requires a density input, so gas mol wt and z must be known or assumed.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close