Custom-designed gas flow monitors. Unmatched knowledge.

A wall mount configuration provides easy access to components.

With the acquisition of Environmental Measurement Research Corporation (EMRC) Bison Engineering has added instrument design, construction, and implementation expertise to our capabilities for serving industrial clients. EMRC has been providing air flow measurement instrumentation services since the 1970s and has developed flue gas instrument application knowledge that is unmatched in the continuous emission monitor (CEM) industry.

All EMRC gas flow monitors are custom-designed to match each gas flow stream condition and integrate with existing electronic components including varying flow ranges, purge times, high moisture conditions and varying pitot lengths. EMRC monitors include a wall or rack mounted unit and electronic interfacing so mass flow requirements can be met on a consistent and verifiable basis.The EMRC instrument package is located off-stack, allowing for ease of maintenance and control, and can be located in an indoor cabinet or outside cabinet, although a thermally controlled space is preferred for ease of maintenance and peak performance.

Product Benefits

EMRC monitors deliver reliable, consistent results because they are designed by stack testers with over 40 years of combined experience who understand the complexity of stack flows for each application. Here are a few benefits our customers realize using an EMRC monitor:

  • Uptime typically exceeds 99.99%.
  • The system can operate in explosion hazard situations because no utilities are required at the stack or duct.
  • Calibration and purging are fully automated.
  • There is no need to send the monitor back to the factory for periodic calibration. The design includes an onboard primary reference method for manual calibration.
  • In situ sensors can be designed to operate in gas streams with extreme characteristics such as high corrosivity, temperature, moisture content, and particulate loading.
  • Because the monitor is based on relatively basic physical principles, installation and maintenance costs are low.
  • Application-specific monitor and installation design deliver flexibility and long-lasting accuracy.

MRC gas flow monitors combine innovation with ultra-reliable, proven technology.

A rack mount design combines a space-saving configuration with ultra-reliable, proven technology.

Today’s models can easily be integrated into a bank of existing gas analyzers, and the front panel configuration reduces the need for additional test equipment. It’s easy to set up, and should process variables change, it’s easy to rearrange. EMRC monitors – each custom designed for your application – employ leading edge technology that ensures compatibility with future advances in the industry.

The key advantages provided by EMRC designed gas flow monitors are simplicity and quality – in design, installation, components and maintenance. That simplicity ensures low installation costs and ease of maintenance. The quality components result in fewer downtimes and lower maintenance costs. One of the key quality components we use is a Rosemount transducer that is consider the best in the industry. The Rosemount transducer is preferred over other models as it has proven to be more reliable and more accurate as compared to lower priced magna helic models.

We believe in the quality of our monitors so much that we provide free technical support via phone or email and do not phase out repairs for older models until our suppliers stop making the parts. We will also send technicians on-site at competitive rates.

Product Advantages

EEMRC monitors meet industry demands requiring simplicity and regulatory compatibility. For example:

In-situ Sensor

The in situ sensor is a stack or duct-mounted heavy duty S-type pitot, manufactured to withstand corrosion, high temperatures, and other hostile conditions. Plugging is avoided via backpurging, as necessary.

Advantages include:

  • Sensor replacement cost is minimal
  • Methodology is EPA method #2
  • Only the sensor is mounted on the stack/duct, minimizing maintenance

In-situ Flow Sensor

The in-situ flow sensor employs a variety of designs and appropriate materials to fit a wide variety of flow measurement applications.

Subsystems include:

  • Pressure signal conditioning interface
  • Differential pressure transducer
  • Temperature measurement (type K thermocouple or RTD
  • Primary reference and pressure auto-calibration subsystem

Instrument Equipment

All instrument equipment is located at convenient locations.

Advantages include:

  • Minimal maintenance, conducted under ideal conditions
  • Monitor can be centrally located with other monitoring equipment
  • Simplified operation and daily calibration


Monitors are calibrated dynamically (auto-cal and manual primary reference).

Advantages include:

  • Signal output is easily verified against EPA #2 standards via onboard manometer
  • Dynamic (pressure) auto-calibration is included

Sample Conditioning Module

Sample conditioning module allows for the accurate determination of gas flow above ~5 FPS.

Advantages include:

  • Sources with high levels of static variation can be monitored with a minimum of interference
  • Very hostile in situ conditions can be monitored without endangering expensive instruments

The sincerest form of flattery is imitation and our competitors have copied parts of our model, but they have never been successful at duplicating our simplicity, quality and reliability!

For more information about EMRC monitors, their applications, our design capabilities, please complete the Request for Quote form. For technical support, please contact Sam Zierke at 406.896.1716.