Industrial Airflow Measurement Technology
The Right Solutions for Demanding Environments
Accurate, repeatable airflow measurement is critical for safe, efficient industrial operations—from combustion air and process exhaust to pollution control and energy management. Air Monitor’s industrial technologies are engineered to handle distorted, turbulent, and dirty gas flows while maintaining high accuracy and long-term stability.
Read on to learn more about the core technologies that set Air Monitor apart as a unique and powerful solution for airflow measurement.
The Air Monitor Difference
See Air Monitor’s Approach vs Traditional DP
| Aspect | Traditional DP Systems | Air Monitor Technology |
|---|---|---|
| Velocity pressure measurement | Uses reference pressure, needs correction factors | Measures true velocity pressure directly |
| Angular sensitivity | Accuracy affected by angular flow – requires correction | ±30° pitch/yaw without extra correction |
| Low-range DP capability | Limited low options | Ultra-low DP down to 0.05 in. w.c. with stability |
| Zeroing/calibration | Periodic manual zeroing needed | AUTO-zero self-calibrating function |
| Dirty gas handling | Ports can foul without manual cleaning | AUTO-purge III automated cleaning |
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Straight Run and Airflow Conditioning
When Tight Installation Points Require a Better Solution
Straight Run Requirements in Facilities
Most industrial installations do not have the luxury of long, straight duct runs ahead of the airflow sensor. Elbows, dampers, and transitions can create swirl and profile distortion that reduce measurement accuracy. Air Monitor designs its technologies to perform in these real‑world layouts and helps engineers understand when additional conditioning will be beneficial.
Honeycomb Cells for Flow Conditioning
To improve accuracy in short or disturbed runs, Air Monitor offers honeycomb cell airflow conditioning that straightens flow and reduces swirl before it reaches the sensing array. This conditioning helps restore a more uniform velocity profile, enabling multi‑point averaging technologies to achieve their specified performance even when straight‑run distances are limited.
Key benefits from flow conditioning
- Improves accuracy in short, constrained duct sections.
- Reduces swirl and profile distortion from elbows, dampers, and fittings.
- Enables reliable measurement where “ideal” layout is not possible.
Single-point vs Multi-point Measurement
Why Multi-point Averaging Matters
In large ducts and stacks, airflow rarely has a uniform velocity profile. Single‑point probes measure only one location, which can lead to significant error when flow is stratified or distorted. Air Monitor’s multi‑point averaging pitot technologies sample the flow at many points across the duct to calculate a true average velocity.
This approach reduces sensitivity to local disturbances and provides a more stable signal for combustion control, process optimization, and emissions compliance.
| Aspect | Single-point and Low Sensor Density Probes | Air Monitor Multi-point Averaging Pitot |
|---|---|---|
| Measurement location | One point in duct | Multiple points across the duct cross-section |
| Sensitivity to profile | Highly sensitive to stratification | Averages profile for more representative airflow |
| Performance in disturbed flow | Often poor in swirl or non-uniform velocity | Designed for distorted industrial flow profiles |
| Typical use | Low accuracy or flow (on/off ) switch, long straight duct runs, small ducts, simple systems | High accuracy, short duct runs, stacks, critical combustion systems, process control systems |
Turbulent and Angular Airflow Challenges
Measuring in Turbulent, Angular Flow
Industrial ductwork often includes short runs, tight elbows, dampers, and take‑offs that create turbulence and angular flow (pitch and yaw). Many conventional differential pressure probes lose accuracy when flow is not perfectly aligned with the sensing ports.
Air Monitor’s multi‑point technologies are engineered to maintain accuracy in the presence of turbulence and angularity, with tolerance to pitch and yaw angles that would otherwise require correction factors. By capturing true velocity pressure across the flow profile, our systems deliver reliable data even where ideal installation conditions cannot be met.
Benefits in challenging flow
- Maintains accuracy in swirl and non‑uniform velocity fields.
- Reduces or eliminates the need for empirical correction factors.
- Supports tighter control of combustion, process temperature, and emissions.
Ultra-low Differential Pressure Transmitters
Benefits of Ultra-low Range Capabilities
Accurate airflow measurement in large ducts and stacks often requires reading extremely low differential pressures. Traditional transmitters may be unstable or noisy at these ranges, making precise control difficult.
Air Monitor’s ultra‑low differential pressure transmitters are engineered for stable measurement at very low inch‑water column levels while maintaining repeatability and long‑term reliability. When combined with multi‑point pitot arrays, they provide direct velocity pressure measurement for accurate, real‑time airflow.
Key Transmitter Capabilities
- Ultra‑low differential pressure ranges for large ducts and low flows.
- Stable, repeatable signal for closed‑loop control.
- Designed to work with multi‑point airflow sensors and advanced functions like AUTO‑zero.
Plant Transmitter vs Air Monitor’s Complete System Solution
Beyond a Plant Transmitter
Many facilities start with a standard plant differential pressure transmitter connected to a basic flow element. While this can work in simple, clean applications, it often struggles with ultra‑low pressure ranges, drift over time, and dirty gas environments.
Air Monitor’s complete solutions pair purpose‑engineered multi‑point airflow sensors with ultra‑low differential pressure transmitters, automatic zeroing, and optional purge systems. This integrated approach is designed specifically for combustion airflow, process air, and dirty gas applications, providing calibrated performance as a system.
Plant Standard Transmitter
- Limited capability at low differential pressures.
- Manual zeroing and calibration required.
- No purpose‑built purging or fouling management.
Air Monitor Complete System Solution
- Ultra‑low range differential pressure measurement down to very low in. w.c. levels with stability.
- AUTO‑zero self‑calibrating function to reduce drift and manual maintenance.
- Optional AUTO‑purge III for dirty gas to keep sensing ports clean.
Explore complete airflow measurement systems.
Auto-purging and Low Maintenance
Dirty Gas Handling
In dirty gas streams—such as coal‑fired boilers, biomass systems, and process exhausts—sensing ports can plug with ash and particulates, degrading accuracy and increasing maintenance. Manual cleaning requires downtime and exposes staff to harsh environments.
Air Monitor’s AUTO‑purge III system automatically delivers purge air through the sensing ports to keep them clear in dirty gas applications. This helps maintain reliable velocity pressure measurement over time and reduces manual cleaning requirements.
Low-maintenance Advantages of Automated Purging
- Automatic port cleaning in dirty gas streams.
- Less manual maintenance and improved uptime.
- More consistent, reliable airflow data for combustion and process control.
AUTO-zero Function for Long-term Stability
Even high‑quality transmitters can drift over time due to temperature changes, component aging, and environmental factors. Without regular zero checks, this drift can translate into significant airflow measurement error.
Air Monitor’s AUTO‑zero function is a self‑calibrating feature that automatically checks and corrects the transmitter zero at programmed intervals. By eliminating accumulated drift, AUTO‑zero helps keep airflow measurements within specification over long periods with minimal manual intervention.
Benefits of AUTO-zero include
Reduces accuracy drift for improved long-term accuracy and reliability.
Minimizes the need for manual zeroing and factory or field recalibration.
Supports critical applications such as combustion control and process safety.
Manufacturing Capabilities
Industrial-grade Fabrication and Quality
Air Monitor designs and manufactures its industrial airflow measurement technologies to withstand demanding environments and long service life. From multi‑point averaging pitot arrays to ultra‑low differential pressure transmitters and purge systems, each component is built for accuracy and durability.
Our manufacturing capabilities include precision fabrication, assembly, and calibration tailored specifically to airflow measurement technologies. This vertically integrated approach helps ensure that the complete measurement system—sensor, transmitter, and accessories—performs as specified in the field.
