---
title: Dedicated Gas Flow Meters for Wastewater
description: Explore Sierra Instruments’ precision gas flow measurement solutions for aeration control, digester gas, and biogas applications at WEFTEC 2026.
---
[](https://www.sierrainstruments.com/)
[](https://www.sierrainstruments.com/)
# The smartest way to measure gas flow
## BioTrak 645i Dedicated Gas Flow Meters for Wastewater
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We are at the booth 1106 - come & visit us!
WEFTEC @ Booth 1106
[](https://info.sierrainstruments.com/hs/cta/wi/redirect?encryptedPayload=AVxigLIEkHRMYozu2moxafzm39p7qaSj6uXpn0npALz0PatL6R4Om%2Ffukubun8ZRKwsNHpxH%2FZSS6JXhxxyeTc%2BX%2BA2njWdngaVRUA9cjWeDaZAKn9rl8FfqV%2BIwfKZ%2Fkrfhef7RYItBVhT45wVNVD0kCqLpJoXaH4o1fROZt5953RmVrVFx%2Fd5%2FQzCzXuxSHDyzjukcCvH%2F5PURqlo%3D&webInteractiveContentId=222053856908&portalId=7893883&hsLang=en)
Discover a smarter way to measure gas flow with the accuracy, reliability, and application expertise wastewater professionals need. Visit our **Booth 1106** to experience live demonstrations and discover how Sierra helps optimize aeration, biogas, and wastewater processes.
[](https://info.sierrainstruments.com/hs/cta/wi/redirect?encryptedPayload=AVxigLKUrmxbCBWN3FKJQMU8nh27wpnJnvXtm5XMgYANrBAalX1aVKBwCKST9%2B5fJmxMsyhcQdbLqFHF%2F%2B8ssci4lfLoa7uNHtBhsHQRwF0zAOgZay8RmKq2FgOwDTwUSy0IGy5eKH3NiGORGUVMu5%2FHbEIILM9gifTtXOvGdzaUpWkqkyMEQ97hv8fWCh58LNWnQxFEKRUvGiIJaEg%3D&webInteractiveContentId=222053759849&portalId=7893883&hsLang=en)
## Introducing New 1/2-Inch BioTrak Probe Option
Break free of old technology and upgrade your process with the help of Sierra’s new ½-inch probe option. See how Sierra’s new ½-inch insertion probe option for BioTrak™ thermal mass flow meters give wastewater treatment facilities greater flexibility to upgrade measurement technology in installations with smaller existing process connections at the show.
BioTrak 645i Thermal Mass Flow Meter (insertion model)
BioTrak 645i with Hot tap
BioTrak 645i with remote enclosure
BioTrak 745i Thermal Mass Flow Meter (inline model)
[](https://info.sierrainstruments.com/hs/cta/wi/redirect?encryptedPayload=AVxigLLQrCOmMCl6SANqzmtDckl0wc0%2Fcwi%2BMdkpgLfXB8PBPAtBWJCSaOxGgR3Zl9w1sJiEywZ47XVzSaBiG7AuP3krsvLGGL%2BPiCdSuCpUxAPi8bTuvN7vt%2B0jHCW5aTnFFupNZI%2BPw7BQ8pdmXC02xPAFnCot1od8prvGo6C4HR%2B3Jukz5jrhUlw8zp%2Bx4BXDzY%2BbsBVB97QGM7E%3D&webInteractiveContentId=222064721019&portalId=7893883&hsLang=en)
## Dedicated Gas Flow Meters for Wastewater
- Field programable: pipe size, gas, unites of measure, full rate range
- Remote configuration, optional AC power, hot tap packing gland with retractor.
- Flow conditioners for limited straight run
- 3/4” and 1/2” probe diameters
- Field verification diagnostics
- Robust DigiSense™ sensor design with 3-year warranty
- High Accuracy:
Accuracy: Air: +/-1% of reading +/-0.2% of full scale
Other gases: +/-1.5% of reading +/-0.5% full scale
- Approvals: FM, FMc , CE, ATEX, and IECEx
[](https://info.sierrainstruments.com/hs/cta/wi/redirect?encryptedPayload=AVxigLLrTPS1H8ANyNTpf8OYl8MWPKVyuTtZ8sEDv7SNlL7wD%2B%2Fqrsfc7ZwXCAjG9Oq2MDrqEY7SpAu2Kwws%2F1eG7fXGrTYe%2Fs5rrjrn%2B6OYwWaUPvTGxoeloQmUe1EhFHS85twwUMc3zc6Qu8sF8Avm6rPGBAII7Tkloc2rhvUmLogMfkJbqcU8D0hyljN1dRZYL2rJ08QNO2QVRnQ2hZQOgamj87BCWN6yWkILMeqYy6eYlMKTpbA%2B7Yl3OwP8dQ%3D%3D&webInteractiveContentId=222064604204&portalId=7893883&hsLang=en)
[](https://info.sierrainstruments.com/hs/cta/wi/redirect?encryptedPayload=AVxigLIHdx0XYOB833SUxD5sXFPshS2zBajSQZhC%2FR2ePkDNqmF%2BP5fewFVerTFOBSHJqWlmBa1hcyb7lpznoumg6ix0K8ZoifLfsIS9DEJf7regd4TVAdjejRYM7NxFxOzUUut7Ig6WzcpuYZYNyop03OboDyATnOyRQgIT3Nas0DmJViZPfim138YeoOQhQbFhtc%2BRwWOb3AYH2PYPeqRd4t%2FvuYBsf%2FecLH%2BuAbQViaiJP3aiuhkcOBBkPA%3D%3D&webInteractiveContentId=222064788018&portalId=7893883&hsLang=en)
## Meet the Expert at the booth 1106
#### Speak with Sierra's Wastewater Flow Application Experts
Sierra’s team will be available throughout WEFTEC at Booth 1106 to discuss attendees’ application requirements, installation challenges, upgrades to existing measurement points, and flow measurement strategies for:
- Aeration and blower-air measurement
- Digester gas and biogas monitoring
- Methane measurement
- Cogeneration and waste-to-energy systems
- Flow measurement installations with limited straight-run or other field constraints
## Meet Darin
### Darin Vande Lune
Sales Manager
Americas Central Region
[tel:013038189986](tel:013038189986) [mailto:dvandelune@sierrainstruments.com](mailto:dvandelune@sierrainstruments.com)
## Meet Glen
### Glen Coblentz
Global Industrial Business Manager
[tel:018312331960](tel:018312331960) [mailto:gcoblentz@sierrainstruments.com](mailto:gcoblentz@sierrainstruments.com)
### Get in contact with us
## Learn more about Sierra Instruments
- More than 50 years of flow expertise: Decades of experience in solving demanding industrial and scientific flow measurement challenges.
- **Technology-driven innovation:** More than 20 patents covering Sierra’s sensor technologies and flow measurement innovations.
- **Application-focused engineering:** Expert support for selecting, sizing and configuring instruments around real operating conditions.
- **Global presence, local support:** Access to Sierra flow specialists through more than 150 locations across 50 countries.
- **Support throughout the product lifecycle:** NIST-traceable calibration, repair and field services, complemented by long-term technical support.
## Frequently Asked Questions
What is the BioTrak 645i designed for?
The BioTrak 645i is a thermal mass flow meter developed specifically for municipal and industrial wastewater applications. It accurately measures gas flow in aeration, anaerobic digestion and cogeneration processes.
Which gases can the BioTrak 645i measure?
Using the integrated BioSelect™ menu, operators can select air, methane or digester gas directly in the field. This flexibility allows the meter to support several critical processes within a wastewater treatment facility.
How accurate is the BioTrak 645i?
For air, the BioTrak 645i provides an accuracy of ±1% of reading plus ±0.2% of full scale. For methane and digester gas, accuracy is ±1.5% of reading plus ±0.5% of full scale.
How can the BioTrak 645i help optimize aeration?
By measuring air mass flow directly, the BioTrak 645i gives operators reliable data for matching airflow to actual treatment demand. This supports more precise aeration control, improved process stability and better visibility into blower performance.
What is the difference between the BioTrak 645i and 745i?
The BioTrak 645i is an insertion-style flow meter designed for installation in larger pipes. The BioTrak 745i is an inline version that is integrated directly into the piping system. Both models are available with integral or remote electronics.
Can the BioTrak 645i be integrated into an existing control system?
Yes. The BioTrak 645i supports standard industrial communication options, including HART and Modbus RTU via RS-485. It is also available with AC or DC power input, helping simplify integration into existing plant infrastructure.
Where can I learn more about the BioTrak 645i at WEFTEC 2026?
Visit Sierra Instruments at WEFTEC 2026 to see the BioTrak 645i and discuss your wastewater flow measurement requirements with a Sierra flow specialist. The team can help assess your application, installation conditions and suitable meter configuration.
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