In many industrial and commercial applications, the most practical method for monitoring gas consumption is through flow meters with pulse output.
This article explains how to interpret gas flow meter pulses for accurate monitoring. A common example is the Honeywell Elster® Quantometer QA/QAE, widely used for natural gas, air, and inert gases.
These meters provide precise pulse signals that represent a defined amount of gas flow. Understanding the technical data and selecting the right pulse counter can be confusing at first glance.
Let’s break it down.
LF and MF Pulse Outputs – What Do They Mean?
In the technical specifications, you will typically see two pulse output columns:
- LF Output (E1) – Low-frequency pulses
- MF Output (E200) – Medium-frequency pulses
Each of these outputs represents a fixed number of impulses per cubic meter (imp/m³). For example:
- LF output: 10 imp/m³
- MF output: 500 imp/m³
This means:
- With 10 imp/m³, each pulse represents 0.1 m³
- With 500 imp/m³, each pulse represents 0.002 m³
The MF output generates significantly more pulses for the same volume of gas, making it ideal for applications that require fine measurement resolution and fast sampling rates. The LF output is more relaxed and suitable for general consumption monitoring, where extremely high accuracy is not necessary.
Which Gas Flow Meter Pulses Should You Use?
This depends entirely on your monitoring device:
- If your pulse counter can handle high-frequency pulses (hundreds per second), use MF (E200) to get maximum measurement resolution.
- If your pulse counter supports only slow or moderate pulse rates, or you prefer simplified data processing, use LF (E1).
Choosing the Right Pulse Counter for Gas Flow Meter Pulses
To integrate Honeywell Elster Quantometer outputs into a control or monitoring system, you need a reliable pulse-counting device.
Two suitable options from our portfolio:
- TDI340 – Industrial pulse counter
An industrial pulse counter supporting input frequencies of up to 100 Hz. The device features non-volatile memory that securely stores pulse counts, ensuring no data loss in the event of power failure. With four independent digital inputs, TDI340 can simultaneously collect pulses from multiple gas flow meters, making it well-suited for reliable volume accumulation and industrial measurement applications. - TCW242 – Industrial IoT module
An Industrial IoT module designed for flexible pulse acquisition and remote monitoring. TCW242 can read both LF and MF pulse outputs and provides multiple digital inputs for connecting gas flow meters and other sensors. It enables local data processing and seamless integration with cloud platforms or SCADA systems, making it ideal for remote gas metering, telemetry, and energy monitoring applications.
Conclusion
When selecting a combination of flow meter + pulse counter, always check:
- The imp/m³ value
- Maximum expected pulse frequency at peak flow
Understanding LF vs MF outputs ensures proper device selection and accurate long-term gas consumption measurement.
For flexible and dependable pulse acquisition, TDI340 and TCW242 provide robust solutions for both low-and high-frequency pulse outputs.
Correct interpretation of gas flow meter pulses ensures reliable measurement over time.