The EMRC Gas Flow Monitor System

Reliable Flow Measurement with a trusted system customized for your needs.

The industry’s preferred gas flow monitor.

Since the 1970s, EMRC has been providing air flow measurement instrumentation services and has developed flue gas instrument application knowledge that is unmatched in the continuous emission monitor (CEM) industry. With a customized fit, a proven 99.9% uptime, and knowledgeable tech support, the EMRC Gas Flow Monitor’s simple and reliable design provides the consistent data you need.

Download Equipment Manual

The EMRC Gas Flow Monitor is designed to measure the dynamic pressure of gas flow in a stack. This document outlines the basic measurement principles employed and how the system measures gas flow. The manual also outlines maintenance requirements in an easy-to-access format.

Get the EMRC Gas Flow Monitor Spec Sheet

Find more detailed information about the system’s specifications, applications, sizing, and more on our downloadable spec sheet.

Learn more about EMRC’s Umbilical Tubing

A key component to each EMRC system is the umbilical tubing that goes with it. With a simple design and high-quality materials, our approach makes for strong tubing that holds up through the wear and tear of everyday use. Download our Umbilical Tubing Spec Sheet for more details.

About the product

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. Each one includes 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.

  • Size: EMRC will package to fit the needs of its customers
  • Weight: Wall mount approx. 160-190 lbs. 19” rack mount approx 70 lbs.
  • Power: 115v or 220v Operating Cabinet
  • Temperature: 30° – 120°F (Some units have internal heaters)
  • Probe Temperature: 2000° F (functional limit of probe material)
  • Recorder Outputs: 4-20 ma standard, all others upon request
  • Performance Specifications Sensitivity: 2fps
  • Response Time: 1-2 seconds to 100% of final reading
  • Linearity: +/- 2% of full scale
  • Repeatability: 1 % Zero Drift: 2-3% of full scale Span Drift: 2-3% of full scale
  • Accuracy: 2% of full scale

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 typically 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.

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.

Flow Sensor

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

Systems 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 minimum interference.
  • Very hostile in-situ conditions can be monitored without endangering expensive instrumentation.