EZ320 PMLS – Laser Backward Scattering PM Analyzer

Introduction

Particulate matter, commonly referred to as PM or dust, is one of the important parameters monitored in industrial stack emissions. Industries operating boilers, furnaces, kilns, thermal processes, manufacturing plants, and other emission-generating processes need reliable systems to continuously monitor particulate concentration in their stacks and ducts.

To support accurate and continuous emission monitoring, Envirozone Instruments & Equipments Pvt. Ltd. offers advanced PM Analyzer solutions designed for industrial stack emission monitoring.

The EZ320 PM and EZ320 PMLS are in-situ particulate matter monitoring systems designed for continuous measurement of dust concentration in industrial stacks and ducts. The product range uses two different optical measurement principles: Dual-Pass Transmissiometry and Laser Backward Scattering (LBS).

The PM Analyzer is an NPL-certified and CPCB-approved product, making it suitable for applications where reliable particulate emission measurement and regulatory monitoring are important requirements.

What Is a PM Analyzer?

A PM Analyzer is an industrial monitoring instrument used to continuously measure the concentration of particulate matter or dust present in an emission stream.

Unlike periodic manual sampling, an online PM Analyzer continuously observes particulate concentration and provides real-time measurement data.

This makes PM monitoring useful for:

• Continuous stack emission monitoring

• Environmental compliance

• CEMS applications

• Industrial process monitoring

• Emission trend analysis

• Early identification of abnormal dust levels

• Integration with plant monitoring and automation systems

The EZ320 PM product family is specifically designed for industrial stack and duct applications and provides continuous particulate measurement.

Why Continuous PM Monitoring Is Important

Industrial combustion and manufacturing processes can generate particulate emissions. Changes in fuel quality, combustion conditions, filtration performance, process operation, or dust-control equipment can affect the concentration of particulate matter in the stack.

Continuous PM monitoring helps industries maintain better visibility of their emission conditions.

For example, an unexpected increase in particulate concentration may indicate a problem with emission-control equipment or a change in process conditions. Continuous monitoring can therefore help plant operators identify unusual conditions more quickly.

For industries operating under environmental monitoring requirements, dependable online particulate measurement is an important part of an overall emission monitoring system.

EZ320 PM – Dual-Pass Transmissiometry PM Analyzer

The EZ320 PM is an in-situ particulate monitoring system based on the Dual-Pass Transmissiometry principle.

In this measurement method, a high-intensity light beam passes across the stack and is reflected back through a precision reflector. Suspended particulate matter in the gas stream attenuates the light. The measured reduction in light intensity is then used to determine the particulate concentration.

The catalogue describes EZ320 PM as an advanced in-situ system designed for continuous and reliable dust concentration measurement in industrial stacks and ducts.

Cross-Stack Installation

EZ320 PM uses a cross-stack configuration, with the sensor arrangement installed across the stack.

The catalogue specifies a 180° cross-stack alignment requirement for the EZ320 PM model.

This configuration allows the optical measurement path to pass through the emission stream, providing continuous monitoring of particulate concentration.

EZ320 PMLS – Laser Backward Scattering PM Analyzer

The EZ320 PMLS uses Laser Backward Scattering (LBS) technology for particulate measurement.

A high-stability laser beam interacts with particles in the gas stream. The light scattered back from the particles is detected and converted into particulate concentration.

One of the key advantages highlighted in the catalogue is its single-sided installation.

Unlike transmissiometry-based systems that require alignment across the stack, the EZ320 PMLS can be installed from one side. This can simplify installation and reduce alignment-related maintenance requirements.

Single-Side Installation

The EZ320 PMLS is specified as an in-situ single-sided PM monitoring system.

This design can be particularly useful where access to both sides of a stack or duct is difficult.

Key Features of Envirozone PM Analyzers

The catalogue highlights several features designed for industrial emission monitoring.

High-Accuracy Measurement

The PM Analyzer is designed for stable particulate measurement, with the catalogue specifying accuracy of ≤ ±10% of the reference method and linearity of ±1% Full Scale.

5-Inch Colour Touchscreen

The system incorporates a 5-inch colour capacitive touchscreen HMI, providing an interface for operating and monitoring the analyzer.

Internal Data Logging

An internal SD card is provided for automatic data storage. This can be useful for maintaining measurement records and reviewing historical data.

4–20 mA Analog Output

The analyzer provides an isolated 4–20 mA analog output for industrial system integration.

RS485 Modbus RTU

Digital communication is available through RS485 Modbus RTU, allowing integration with compatible PLC, DCS, SCADA, and data acquisition systems.

Programmable Alarm

The analyzer provides a relay alarm output for safety and limit alerts. This can help operators identify conditions where particulate concentration reaches a programmed limit.

Rugged Industrial Construction

The PM Analyzer uses a fiberglass/glass-reinforced polyester enclosure with IP65/66 protection, as specified in the catalogue. This makes the equipment suitable for demanding industrial environments.

Purge Air System for Stable Measurement

Optical PM monitoring systems require clean optical surfaces for stable measurement.

The catalogue specifies a clean, oil-free purge air supply of 0.5 L/sec at 4 bar. The purge-air arrangement is designed to help keep the optical components clean and support long-term measurement stability.

Proper purge-air quality and regular maintenance are therefore important parts of reliable PM Analyzer operation.

Technical Specifications of EZ320 PM and EZ320 PMLS

The two PM Analyzer models share several important specifications while using different measurement principles.

The specifications above are based on the technical specification table in the Envirozone PM Analyzer catalogue.

PM Analyzer in CEMS Applications

A PM Analyzer can form an important part of a Continuous Emission Monitoring System (CEMS).

In a typical online emission monitoring arrangement, the PM Analyzer is installed at the stack or duct to continuously measure particulate concentration. Its outputs can then be connected to the plant's monitoring or data acquisition infrastructure.

The EZ320 PM and EZ320 PMLS provide both analog and digital communication options, including isolated 4–20 mA and RS485 Modbus RTU.

This enables the PM measurement system to be incorporated into compatible industrial automation and environmental monitoring architectures.

Applications of PM Analyzers

PM Analyzers can be used across industries where particulate emissions from stacks or ducts require continuous monitoring.

Typical applications include:

Thermal Power and Boiler Plants

Boiler combustion processes can generate particulate emissions. Online PM monitoring can provide continuous information about dust concentration in the stack.

Cement Plants

Cement manufacturing involves several dust-generating processes. Continuous particulate monitoring can support emission monitoring at relevant process stacks.

Steel and Metallurgical Industries

Industrial furnaces and metallurgical processes may generate particulate emissions, making continuous PM monitoring important for environmental monitoring.

Chemical and Process Industries

Process industries may require particulate monitoring depending on their manufacturing processes and emission sources.

Waste Treatment and Incineration

Thermal treatment processes can generate particulate emissions. Online monitoring can provide continuous information about stack conditions.

Manufacturing Industries

Various manufacturing operations involving combustion, heating, material handling, or processing can benefit from continuous particulate monitoring.

The suitability of a particular PM Analyzer should always be evaluated according to the stack conditions, application requirements, expected concentration range, installation arrangement, and applicable regulatory specifications.

EZ320 PM vs EZ320 PMLS – Which Technology Is Suitable?

Both technologies are designed for continuous particulate measurement, but their installation principles are different.

EZ320 PM uses Dual-Pass Transmissiometry and requires cross-stack installation with 180° alignment.

EZ320 PMLS uses Laser Backward Scattering technology and is designed for single-sided installation.

Therefore, the choice between the two systems can depend on the physical configuration of the stack, accessibility, installation requirements, and project specifications.

Where access to both sides of the stack is available, a cross-stack arrangement may be suitable. Where installation from only one side is preferred or practical, the single-sided PMLS configuration can offer an installation advantage.

Benefits of an Online PM Analyzer

An appropriately selected and maintained PM Analyzer can provide industries with several benefits:

• Continuous particulate emission measurement

• Real-time monitoring of dust concentration

• Support for environmental compliance monitoring

• Reduced dependence on periodic manual observation

• Automatic data logging

• Industrial communication through RS485 Modbus RTU

• 4–20 mA integration

• Programmable alarm functionality

• Compatibility with PLC, DCS and SCADA systems

• Rugged construction for industrial environments

• Simplified installation with the single-sided PMLS option

• Long-term measurement stability with appropriate purge-air management

The catalogue specifically identifies the product as suitable for regulatory emission monitoring and highlights its compatibility with PLC, DCS, and SCADA systems.

Why Choose Envirozone Instruments & Equipments Pvt. Ltd.?

Envirozone Instruments & Equipments Pvt. Ltd. provides industrial environmental monitoring solutions focused on measuring, monitoring, and mitigating emissions.

Its PM Analyzer range combines optical measurement technology with industrial communication, data logging, alarm functions, rugged field construction, and integration capabilities.

The EZ320 PM and EZ320 PMLS are designed to provide continuous particulate monitoring for industrial stacks and ducts, with the choice between cross-stack transmissiometry and single-sided laser backward scattering technology.

As an NPL-certified and CPCB-approved PM Analyzer solution, the product is positioned for industries seeking dependable particulate emission monitoring and regulatory monitoring support.

Conclusion

Continuous particulate monitoring has become an important part of modern industrial emission management. A reliable PM Analyzer enables industries to continuously observe dust concentration, maintain emission records, identify abnormal conditions, and integrate particulate monitoring into their broader CEMS and automation infrastructure.

The Envirozone EZ320 PM uses Dual-Pass Transmissiometry for in-situ cross-stack measurement, while the EZ320 PMLS uses Laser Backward Scattering technology for in-situ single-sided measurement. Both systems provide a measuring range of 0–1000 mg/m³, customizable, along with 4–20 mA output, RS485 Modbus RTU communication, SD-card data storage, relay alarms, and IP65/66 protection.

For industries looking for a reliable solution for continuous stack particulate monitoring, Envirozone Instruments & Equipments Pvt. Ltd.'s NPL-certified and CPCB-approved PM Analyzer range offers modern optical measurement technologies designed for industrial emission monitoring applications.

Envirozone Instruments & Equipments Pvt. Ltd.
Measure. Monitor. Mitigate.

NPL-Certified and CPCB-Compliant Gas Analyzers: Their Role in Industrial Emission Monitoring- Envirozon Instruments& Equipments Pvt. Ltd.

Introduction

Industrial processes that involve combustion, chemical reactions, heating, or material processing can generate gases that need to be continuously monitored. Accurate measurement of stack emissions is therefore an important part of environmental monitoring, process control, and regulatory compliance.

Gas analyzers used in Continuous Emission Monitoring Systems (CEMS) help industries measure important gaseous pollutants and process gases in real time. When an analyzer is supported by appropriate certification, calibration traceability, and applicable CPCB requirements, it can provide industries with greater confidence in the accuracy and reliability of their emission monitoring data.

Modern industrial gas analyzers are available with different sensing technologies depending on the gas being measured, concentration range, process conditions, and required measurement accuracy.

According to the supplied product brochure, the analyzer range includes NDIR, UV-DOAS, Zirconia, and TDLAS-based technologies for applications involving multiple industrial gases.

What Is an Industrial Gas Analyzer?

An industrial gas analyzer is an analytical instrument designed to determine the concentration of specific gases in a process or emission stream.

In stack emission monitoring, the analyzer receives a representative sample from the chimney or process exhaust and measures gases such as:

• SO₂

• NOx

• CO

• CO₂

• O₂

• Cl₂

• NH₃

• CH₄

• H₂S

• HCl

• HF

• H₂O

The exact gases measured depend on the analyzer model and sensing technology.

The supplied brochure specifies NDIR analyzers for gases such as CO, CO₂, SO₂ and NO, UV-DOAS analyzers for gases including SO₂, NO, NO₂, NH₃, O₃ and Cl₂, and Zirconia analyzers for oxygen measurement.

Why NPL Certification and CPCB Compliance Matter

For industries, emission monitoring data is not simply a number displayed on an instrument. The data may be used for environmental monitoring, regulatory reporting, process evaluation, and corrective action.

This makes measurement reliability extremely important.

Where applicable, NPL-related calibration traceability can provide confidence that measurements are linked to recognized reference standards. Similarly, CPCB requirements and applicable technical specifications are important when gas monitoring equipment is deployed for regulatory emission monitoring.

Industries should therefore evaluate not only the analyzer itself but the complete monitoring system, including:

• Measurement technology

• Calibration procedure

• Sampling system

• Gas conditioning

• Analyzer accuracy

• Zero and span stability

• Data communication

• Data logging

• CEMS integration

• Maintenance and validation procedures

A certification or compliance claim should always be supported by the relevant certificate, approval, test report, or applicable regulatory documentation for the specific analyzer model and application.

Role of Gas Analyzers in CEMS

Continuous Emission Monitoring Systems are designed to provide continuous information about emissions from industrial stacks.

A typical CEMS arrangement includes a sampling probe, sample line, gas conditioning system, filters, moisture removal, calibration gas arrangement, analyzer, and communication system.

The CEMS pneumatic diagram in the supplied brochure illustrates a sampling arrangement incorporating a heated sample line, gas cooler, moisture sensor and filter, NOx converter, calibration gas cylinders, aspirator/pump, and gas analyzer.

This demonstrates an important point: accurate gas measurement depends on the complete sampling and conditioning system, not only on the analyzer.

Sample Handling and Conditioning

Industrial stack gases can contain high temperatures, moisture, dust, and other interfering components. If the sample is not properly handled before it reaches the analyzer, measurement accuracy can be affected.

The brochure describes two sample-handling approaches.

Hot & Wet Extraction

In a hot and wet extraction system, the sample is extracted from the stack using a heated sample probe and transferred through a heated line to prevent condensation. The sample is subsequently cooled and moisture is removed before analysis.

Cold & Dry Extraction

In a cold and dry extraction system, the sample is cooled and moisture is removed near the sampling point. The conditioned sample is then transported to the analyzer through a PTFE line.

Selecting the appropriate sampling and conditioning arrangement is important because different industrial processes have different gas temperatures, moisture levels, dust loading, and chemical compositions.

Major Gas Analyzer Technologies

1. NDIR Gas Analyzer

NDIR, or Non-Dispersive Infrared technology, is commonly used for measuring gases that absorb infrared radiation.

According to the supplied brochure, the NDIR analyzer range can be used for gases including CO, CO₂, SO₂ and NO, depending on the model.

NDIR technology can be useful in industrial applications where stable and continuous measurement of selected infrared-active gases is required.

2. UV-DOAS Gas Analyzer

UV-DOAS, or Ultraviolet Differential Optical Absorption Spectroscopy, uses ultraviolet absorption characteristics to identify and quantify selected gases.

The brochure lists SO₂, NO, NO₂, NH₃, O₃ and Cl₂ among the gases that can be measured using UV-DOAS technology.

This technology can be particularly useful where selective measurement of multiple gas components is required.

3. Zirconia Oxygen Analyzer

Zirconia-based analyzers are used for oxygen measurement.

Oxygen measurement is important in combustion-related processes because oxygen concentration can provide valuable information about combustion conditions and excess air.

The supplied brochure specifically identifies Zirconia technology for O₂ measurement.

4. TDLAS Laser Gas Analyzer

TDLAS stands for Tunable Diode Laser Absorption Spectroscopy.

The brochure describes the EZ320 TDLAS Laser Gas Analyzer as an extractive gas monitoring system designed for real-time measurement of critical industrial gases. It lists HCl, HF, NH₃, CH₄, O₂, H₂S, CO₂ and H₂O among the measurable gases.

The brochure highlights the system's selective measurement, fast response, and resistance to interference, making TDLAS technology suitable for demanding industrial process environments.

Important Technical Features

The gas analyzer specifications shown in the brochure include:

• Extractive measurement type

• Measuring range up to approximately 0–1000 ppm for the general gas analyzer range, with other ranges available on request

• Accuracy of ±2% of reference measurement

• Repeatability of ≤ ±1% of full scale

• Response time (T90) of ≤60 seconds

• Zero drift of ≤ ±1% F.S. per week

• Span drift of ≤ ±1% F.S. per week

• Manual, automatic, or remote calibration depending on model

• Approximately 0.8 LPM sample flow rate

• 7-inch colour touchscreen HMI depending on model

• 4–20 mA analog outputs

• RS485 communication with Modbus RTU

• Potential-free alarm relay contacts

• 19-inch rack mounting

• 220 VAC ±10%, 50 Hz power supply

These specifications are taken from the technical specification table in the supplied brochure.

The TDLAS model shown on the third page has a specified measuring range of approximately 0–50 ppm, with other ranges available on request, and includes similar communication, calibration, display, and rack-mounting features.

Role Across Different Industries

Gas analyzers can play an important role in industries where combustion gases, process emissions, or chemical gases need to be monitored.

Power and Boiler Plants

Boilers and combustion systems generate gases such as SO₂, NOx, CO and CO₂. Continuous monitoring can help operators understand emission conditions and identify changes in combustion performance.

O₂ measurement can also be useful for evaluating combustion conditions and excess-air levels.

Cement and Mineral Industries

Cement and mineral-processing operations involve high-temperature processes and significant exhaust gas streams. Gas analyzers can support continuous emission monitoring and help operators track relevant gaseous parameters.

Chemical and Process Industries

Chemical plants may handle gases such as HCl, HF, NH₃, Cl₂, H₂S and other process gases.

For these applications, selecting the correct measurement technology is particularly important because gas composition and concentration can vary considerably from one process to another.

Waste and Incineration Applications

Thermal treatment and incineration processes can generate multiple gaseous pollutants. Continuous gas analysis can help industries monitor their emission profile and identify abnormal operating conditions.

Steel and Metallurgical Industries

High-temperature industrial processes can generate CO, CO₂, SO₂, NOx and other gases. Gas analyzers can provide continuous information for both environmental monitoring and process optimization.

Gas Analyzers for Environmental Compliance

One of the most important roles of a gas analyzer is to provide reliable measurement data for environmental monitoring.

A properly configured monitoring system can continuously measure selected emission parameters and transmit the data to a plant monitoring or data acquisition system.

The supplied brochure identifies the analyzers as being designed for continuous emission monitoring, process control, and environmental compliance across industrial applications.

For industries subject to regulatory monitoring requirements, the complete CEMS installation should therefore be designed according to the applicable regulatory requirements and project specifications.

Data Communication and Remote Monitoring

Modern gas analyzers are increasingly integrated with plant automation and environmental data systems.

The supplied analyzer specifications include:

4–20 mA analog output for industrial signal integration and RS485 Modbus RTU communication for digital communication.

Remote calibration is also identified as an available feature depending on the model.

These features can make the analyzer easier to integrate with CEMS panels, PLC/SCADA systems, data acquisition systems, and other industrial monitoring infrastructure.

Why the Complete CEMS System Matters

Choosing a gas analyzer based only on the name of its sensing technology is not enough.

For reliable industrial emission monitoring, attention should also be given to:

1. Sampling probe design

2. Heated or unheated sample lines

3. Gas cooling

4. Moisture removal

5. Filtration

6. NOx conversion where required

7. Calibration gas arrangement

8. Sample flow control

9. Analyzer calibration

10. Data communication

11. Preventive maintenance

12. Validation and performance checks

The CEMS arrangement illustrated in the supplied brochure demonstrates how several of these components work together before the sample reaches the analyzer.

Benefits for Industrial Operations

A properly selected and maintained gas analyzer can provide several operational benefits:

• Continuous visibility of emission parameters

• Better understanding of combustion conditions

• Faster identification of abnormal emission levels

• Support for environmental compliance

• Improved process monitoring

• Integration with plant automation systems

• Remote monitoring and calibration capabilities on supported models

• Reliable long-term measurement when properly maintained

How Industries Should Select a Gas Analyzer

Before purchasing or installing a gas analyzer, industries should consider the following questions:

Which gases need to be measured?
The analyzer technology should be selected according to the required gases.

What is the expected concentration range?
The measurement range should match the actual process and regulatory monitoring requirements.

What are the stack conditions?
Temperature, moisture, dust, pressure, and corrosive components can influence the sampling system design.

Is extractive or another measurement arrangement appropriate?
The sampling architecture should be selected according to the process conditions and analyzer technology.

What certification and compliance documentation is required?
Where regulatory monitoring is involved, industries should verify the applicable CPCB requirements and obtain the relevant certification, calibration, approval, and technical documentation for the specific equipment.

How will the analyzer communicate with the monitoring system?
4–20 mA and RS485/Modbus interfaces can facilitate integration with industrial control and data acquisition systems, depending on the project configuration.

Conclusion

Gas analyzers are a critical component of modern industrial emission monitoring systems. Their role extends beyond simply measuring gases: they provide continuous information that can support environmental monitoring, process control, operational decision-making, and regulatory compliance.

Technologies such as NDIR, UV-DOAS, Zirconia, and TDLAS provide different approaches for measuring gases under different industrial conditions. The supplied product range demonstrates how these technologies can be combined with sample handling, gas conditioning, calibration, communication, and CEMS infrastructure to create a complete monitoring solution.

For industries looking for reliable emission monitoring, the right approach is to evaluate the complete gas analysis and CEMS solution—including analyzer technology, sampling and conditioning, calibration, communication, maintenance, and applicable certification or regulatory requirements.

A properly selected and properly maintained gas analyzer can help industries move toward more accurate, continuous, and dependable emission monitoring while supporting their broader environmental management objectives.