Field-Update For Gas Composition Changes

qMix Gas Mixing Feature

Powerful, gas mixing software to create custom gas mixtures in the field
Per meter license gives unlimited custom gas mixtures and uploads per meter serial number
Maintain flow meter accuracy if gas composition changes
No need to send unit back to the factory if gas composition changes
Avoid costly recalibration

Overview

qMix is a powerful, user-customizable gas mix feature included with everyQuadraTherm^®thermal mass flow meter. qMix provides the ultimate gas flow measurement field flexibility by allowing you to create unlimited custom gases or gas mixtures to compensate for gas compositional changes in the field. Additionally, Sierra's breakthrough QuadraTherm qMix RealTime Flare Measurement System (FMS) delivers real-time flare gas flow measurement to accurately measure flows down to 0.1 fps, meeting the full range of EPA regulations.

Learn more about how oil and gas engineers leverage the technology offered within this thermal flow meter: watch How it Works video qMix RealTime Flare Measurement System video and read Flare Gas Application Tech Note or Solving The Flare Gas EPA Compliance Challenge with Game-Changing qMix RealTime Flare Measurement System (FMS).

Download Flare Gas Mass Flow Measuring Application Tech Note

Get Started with qMixUse qMix when the gas composition changes in the pipe or when moving the meter to another location with a different gas composition. The major benefit is that now for the first time with thermal technology you can retain accuracy without returning the meter to the factory for recalibration.

qMix Activation
There are two ways to activate the qMix app for your QuadraTherm 640i/780i: 1.) Purchase a qMix license per 640i/780i serial number upfront at point of purchase. 2.) Purchase a qMix license in the field for existing 640i/780i customers. View qMix Activation Quick Start Guide
Watch qMix Tutorial Video.

Upfront Purchase of a qMix License
The recommended way to activate the qMix app for your QuadraTherm 640i/780i is to purchase a qMix license for $615.00 per serial at time of purchase by using the model code qMix found the 640i/780i price list (must activate each meter per serial number).

Existing Customers: Purchase qMix License for Meters Already in the Field (firmware 2.0.59 or higher)
To upgrade an existing QuadraTherm 640i/780i meter with qMix in the field, you must purchase and activate a qMix license (one per serial number).

Download the SIP.

Product Benefits

Through an easy-to-use software interface, qMix allows you to:

Field adjust and maintain flow meter accuracy if gas composition changes
Avoid costly recalibration; Once qMix has been installed, no need to send unit back to the factory if gas composition changes
Create and upload an unlimited number of gas mixtures onto one meter (license on a per meter serial number basis)
Save custom gas mixtures onto your personal "My Gases Database" for later use
Benefit from Sierra's proprietary, ever improving, qTherm Gas Databaseto download more accurate gases and gas mixtures

NOTE:For QuadraTherms withserial numbers 339589 or lower, please visit Sierra's Document & Downloads Archive Page to access documentation applicable to your device.

Documents & Downloads

	File Title	Version	Release Date
Datasheets(1)
	QuadraTherm 640i /780i Series Technical Datasheet	V2 QTherm V1	08/06/2025
Manuals(2)
	File Title	Version	Release Date
	qMix Gas Mixing Feature Instruction Manual	V2.A	08/06/2025
	QuadraTherm 640i/780i Series Instruction Manual	V2.A	08/06/2025
Guides(1)
	File Title	Version	Release Date
	QuadraTherm 640i/780i qMix Quick Install Guide	P/N 47-0616 V2.A	08/06/2025
Software(1)
	File Title	Version	Release Date
	QuadraTherm 640i/780i Series Product Software (SIP)	v2.0.0.12.	08/06/2025
Additional Documentation(1)
	File Title	Version	Release Date
	Big-3 Overview Brochure	V1	06/29/2017