Laser Gas Analyser

ZSS laser gas analysers provide innovative combustion optimization technology - perfect for incinerators, industrial boilers, power, steel and chemical plants.

ZSS Laser Gas Analysers

The in-situ method enables very rapid measurement.

laser gas analyserszss

Long-term stability and low maintenance.

ZSS Laser Gas Analysers for: waste incinerators, district heating, industrial boilers and chemical plants.

NH3 - HCI - CO - O2 - CO2 - CH4

ZSS Laser gas analysers provide continuous measurement of gas concentration

laser analysers zss series


Absorption spectrum

The analyser uses near infrared semiconductor laser and measures the change in absorption wavelength to determine the gas concentration.

absoprtion spectrum shema

Energy savings, reduced maintenance

  1. Energy consumption ≤ 80 VA
  2. Maintenance work ≤ twice a year
  3. With no need for sampling devices and preconditioning, consumable parts and maintenance operations.

blueprint of the comparison with the sampling method

Zero point stability

Purge system reduces the risk of zero drift due to contamination

Fast response within 2 seconds

Compared to the ion electrode (sampling) method, the direct measurement provides remarkably faster response.

co o2 analyser available

CO + O2 analyser available

Simultaneous measurement of CO and O₂ enables precise control of air-fuel ratio while reducing the cost of installation and maintenance.

  • ppm CO + O2 (high-temperature)
    • vol % CO + O2
  • ppm CO + O2 (instrument air purge)
  • CO + CO2

Instrument air purge available

O₂ analyser for combustion control accepts instrument air purge.


Operating principle and Measurable Components

Operation is based on a semiconductor laser that guarantees precise, reliable measurement. In-situ technology enables direct measurement of gaseous components, eliminating the need for sampling.

The heart of this analyser lies in its use of a laser as a light source, specifically a near-infrared semiconductor laser. This advanced technology enables in-situ measurement of gaseous components such as NH3, HCI, CO, O2, CO2, and CH4. The versatility of these measurements makes them an indispensable tool in a wide range of industrial applications.

Advanced technical features

Light Source and Laser Class

The light source, a near-infrared semiconductor laser, guarantees high accuracy in the measurement of gas concentrations. It's important to note that the laser class used is CLASS 1, with exceptions for high-temperature versions and those with air purging of O2 analysers, which correspond to CLASS 3B, ensuring safe use.

Power and Consumption

The analyser is compatible with supply voltages ranging from 100 to 240 Vac at 50/60 Hz, making it easy to integrate into a variety of industrial environments. Power consumption is limited to 80 VA, underlining the energy efficiency of this device.

Calibration interval

Maintaining measurement accuracy is essential, and the analyser suggests a calibration interval of every 6 months. This period may vary according to environmental conditions.

Display and Information

The backlit LCD screen offers a user-friendly interface, displaying crucial information such as measured component, concentration (instantaneous value, average, corrected instantaneous O2 value, corrected average O2 value), and alerts.

Weight, dimensions and protection class

The analyser has been designed with ease of installation in mind. The weight of the receiver and transmitter is around 10 kg each, while the controller weighs around 8 kg. The various dimensions (receiver, transmitter and controller) allow flexibility in placement. What's more, the IP65 rating underlines the robustness of the device, protecting it from the elements.

Exceptional Performance

The performance of this in-situ laser analyser is underlined by its fast response, high repeatability, and ability to maintain long-term accuracy. With features such as minimal zero drift and resistance to interference, it is an ideal choice for a wide range of industrial applications.

Rapid Response for Real-Time Monitoring

The response speed of the ZSS analyser is impressive, reaching a time of less than or equal to 4 seconds, and even faster, ≤ 2 seconds, for the high-speed version. This ability to deliver near-instantaneous results enables real-time monitoring, essential in dynamic industrial environments.

Repeatability and linearity

The analyser maintains exceptional repeatability, limited to ≤ ±1.0% of range, depending on components and measurement scales. This feature is essential to guarantee consistent results. In the case of combined CO + O2 measurement, accuracy is maintained at ±2% of full scale.

Linearity, another crucial quality, also remains outstanding, with a tolerance ≤ ±1.0% of full scale, depending on components and scales. For CO + O2 measurement, linearity remains excellent, with an accuracy of ±3% of full scale.

Zero drift and the effect of interference

Fuji Electric's ZSS laser analyser offers exceptional stability with zero drift limited to ≤ ±2.0% of full scale over a period of 6 months, depending on the component and measurement scale. CO + O2 measurement maintains even more impressive accuracy, with drift limited to ±4% of full scale over the same period.

The effect of interference is minimized, with a maximum variation of ≤ ±2.0% of full scale. This ability to resist interference contributes to the reliability of results in complex environments.

Detection limit

The in-situ laser analyser also excels in terms of sensitivity, with a remarkable detection limit of no more than 1% of the minimum scale. This ability to detect very low concentrations is essential for accurate monitoring, even in conditions where gas levels are minimal.

Input/output signals

Analog outputs for maximum flexibility

The analyser offers analog outputs, with a signal range of 4-20 mAdc or 1-5 Vdc, with a choice of 2 or 4 points. These outputs enable transmission of the measured value as well as the corrected oxygen (O2) value. In addition, flexibility is maximized by the ability to switch between instantaneous and average values, offering greater adaptability to specific monitoring needs.

Analog inputs for precise correction and compensation

The analyser 's analog inputs are essential for accurate correction and compensation of measurements. Key parameters such as sample gas pressure, temperature, flow velocity, O2 content, water concentration and air purge pressure are integrated via 2-point 4-20 mApp signals. These inputs play a crucial role in measurement adjustment, ensuring maximum accuracy even under variable conditions.

Digital outputs for sophisticated control

Digital outputs enhance the control capabilities of theanalyser with a 6-point relay contact output. These outputs enable management of low light transmission, high and low limit alarms,analyser faults, calibration processes in progress or measurement hold, power failure, and installation faults. This versatility offers sophisticated control for proactive monitoring.

Digital inputs for remote control (Optional)

As an option, the analyser can be equipped with digital inputs via a 3-point photocoupler. These inputs enable advanced functions such as resetting the average value to zero, alternating between instantaneous and sliding average values, and holding the measurement remotely. This option adds an extra dimension to remote device management.

Installation environment

Extended ambient temperature for maximum adaptability

The analyser is designed to operate over a wide range of ambient temperatures, ensuring reliability in diverse industrial environments. The receiver and transmitter can operate in conditions ranging from -20 to +55°C, while the controller is suitable for temperatures from -5 to +45°C. This extended range means it can be used in applications where temperature variations are unavoidable.

Humidity Control to Preserve Measurement Accuracy

Humidity management is crucial to maintaining measurement accuracy. The device is designed to operate in conditions where ambient humidity does not exceed 90% RH (relative humidity). This ensures that measurements remain stable and reliable even in potentially humid industrial environments.

Optical path length for tailored performance

The optical path length, an essential parameter for CO + O2 measurements, is adaptable to the specific needs of the application. With a range from 0.5 to 10 m,analyser offers optimum flexibility to suit a variety of configurations and installation requirements.

Standard flanges for easy integration

Integration of the ZSS analyser into existing systems is simplified thanks to standard flanges. Options include JIS 10K, 50A, 100A, DN50/PN10, or ANSI # 150 2B, offering compatibility with different standards and industrial plant configurations.

Purge gas for a clean environment

An efficient purge system is essential to maintain optical clarity and measurement accuracy. The specific table provided indicates the recommended purge gases, with a minimum pressure of 0.3 MPa and a flow rate of at least 20 L/min, ensuring a clean and clear environment foranalyser operations.

Gas conditions for optimum performance

Gas conditions play a crucial role inanalyser performance. Compliance with specifications, such as humidity limited to ≤50% vol (non-condensing), pressure with a tolerance of ± 10 kPa, and dust levels in line with standard or high-dust versions, guarantees optimum device performance.

Measurable components and ranges

Single beam 1 component analyser



CO (High Scale)

CO (Low Scale)




O2 (High Temperature)

O2 (Instrument air purge)

Single beam 2 components analyser

CO + CO2

Double beam 2 components analyser

Ppm CO + O2 (Instrument Air Purge)

Ppm CO + O2 (High Temperature)

%vol CO + O2

*The measurement ranges described above are for the optical path of 1 m.

Download the brochure boiler combustion solution and laser gas analyser ZSS

Combustion optimization solutions for boilers

Brochures Download

analyser Laser ZSS

Brochures Download

Possible applications for the ZSS analyser

blueprint of a possible applications for the zss analyser

Discover the ZSS laser gas analyser

Fuji Electric's laser gas analysers are designed to help you optimize your combustion performance!

As an instrumentation specialist, manufacturer of pressure transmitters and expert in gas analysis, our expertise extends to all industrial measurement solutions: pressure measurement, flow measurement, level measurement, temperature control, gas analysis and radiation monitoring.