HERTZINNO Online DGA Monitoring Systems provide continuous dissolved gas analysis for transformer condition monitoring and early fault diagnosis.
By tracking dissolved fault gases, moisture, TDCG and gas rate-of-change trends, the systems help operators identify overheating, discharge, arcing and insulation degradation before failures occur.

Model

HZ-DGA-900

Product Type

Online DGA Monitoring System

Measurement Method

Enhanced PAS + Photonic Spectroscopy

Measured Parameters

H₂, CH₄, C₂H₆, C₂H₄, C₂H₂, CO, CO₂, O₂, H₂O

Measurement Cycle

1 hour

Transformer Liquid Type

Mineral oil or ester liquids

Oil Sampling

Vacuum gas extraction

Protection

IP55; IP56 / IP66 customization

GET A QUOTE

Online DGA for Transformer Oil Analysis

HZ-DGA-900 is an online DGA monitoring system designed for transformer condition monitoring and early fault diagnosis. It measures 9 dissolved gases and moisture in transformer oil using photoacoustic spectroscopy, photonic spectroscopy, MEMS IR light source technology and vacuum gas extraction. With a 1-hour measurement cycle, no carrier gas or calibration gas consumables and long-term measurement stability, HZ-DGA-900 helps utilities, substations and data centers monitor transformer health continuously.

9 Gases + Moisture

Online monitoring for transformer fault gases and oil moisture.

1-Hour Cycle

Optical measurement cycle for continuous transformer health tracking.

No Consumables

No carrier gas or calibration gas required for routine operation.

-40℃ to 70℃

Wide operating temperature range for substation and outdoor environments.

Why Online DGA Matters

Detect transformer faults before they become failures.

Dissolved gas analysis is one of the most important methods for transformer condition monitoring. By continuously tracking fault gases, moisture, TDCG and gas rate-of-change trends, online DGA helps operators identify overheating, arcing, discharge and insulation degradation risks before they lead to unplanned outages.

Early Fault Warning

Track dissolved fault gases to identify thermal faults, discharge activity and insulation problems at an early stage.

Continuous Asset Health

Replace periodic sampling with continuous transformer oil monitoring for faster and more reliable condition awareness.

Moisture & Insulation Risk

Monitor moisture trends in transformer oil to support insulation condition assessment and maintenance planning.

Data-driven Maintenance

Use gas concentration, TDCG and rate-of-change data to support fault diagnosis, alarm strategy and asset management.

Enhanced PAS Technology

Advanced optical DGA without gas consumables.

HERTZINNO Online DGA systems combine enhanced photoacoustic spectroscopy, photonic spectroscopy, MEMS IR light source technology and dual-chamber gas detection. This architecture improves long-term stability, reduces maintenance workload and avoids the carrier gas or calibration gas consumables required by many traditional systems.

MEMS IR Light Source Electronically modulated infrared light source design helps avoid mechanical chopper vibration and supports stable optical measurement.

Dual-chamber Detection Two-stage gas absorption improves trace gas sensitivity and supports reliable measurement for transformer fault gases.

Vacuum Gas Extraction Dissolved gases are extracted from transformer oil through vacuum degassing to support repeatable online measurement.

No Carrier or Calibration Gas The optical measurement design reduces routine maintenance and makes the system more suitable for long-term unattended operation.

Online dissolved gas analysis for transformer health monitoring.

HZ-DGA-900 extracts gases from transformer oil through vacuum gas extraction and analyzes target gases using photoacoustic spectroscopy and photonic spectroscopy. MEMS IR light source technology and dual-cell gas detection improve long-term stability, while self-calibration and maintenance-free design help reduce site maintenance workload.

HOW IT WORKS

01

Sampling

Transformer oil is sampled through a vacuum gas extraction process.

02

Gas Extraction

Dissolved gases are separated from the oil for optical measurement.

03

Gas Analysis

PAS, photonic spectroscopy and MEMS IR technology measure fault gases and moisture.

04

Fault Monitoring

Gas concentration, TDCG and rate-of-change data support transformer fault diagnosis.

Model Selection

Choose the right online DGA model

Select DGA500 for essential 5-gas transformer monitoring, or HZ-DGA-900 for advanced 9-gas and moisture analysis in critical transformer applications.

Essential Monitoring

HZ-DGA-500

5-gas online DGA monitor

DGA500 is designed for essential online transformer condition monitoring. It measures key fault gases and trace moisture to support early warning, trend tracking and routine asset health management.

Measures H₂, CO, CH₄, C₂H₂, C₂H₄ and trace moisture.
Suitable for distribution transformers and compact substations.
Uses MEMS IR and dual-chamber design for stable measurement.
Supports 1-hour optical measurement cycle and no gas consumables.

5 gases Plus trace moisture

1-hour Measurement cycle

3-year Standard warranty

No gas No carrier/calibration gas

Advanced Monitoring

HZ-DGA-900

9-gas + moisture online DGA system

HZ-DGA-900 is designed for advanced transformer fault diagnosis and critical asset monitoring. It provides broader gas coverage for high-value transformers, grid substations and power-critical facilities.

Measures H₂, CO, CO₂, CH₄, C₂H₂, C₂H₄, C₂H₆, O₂, N₂ and trace moisture.
Suitable for power transformers, critical substations and data center power infrastructure.
Combines PAS, photonic spectroscopy, MEMS IR and dual-chamber detection.
Designed for long-term stability, autocalibration and maintenance-free operation.

9 gases Plus trace moisture

1-hour Measurement cycle

5-year Standard warranty

Critical For high-value assets

Selection Item

DGA500

HZ-DGA-900

Positioning

Essential online DGA monitoring

Advanced online DGA monitoring

Gas Coverage

5 gases + moisture

9 gases + moisture

Best For

Distribution transformers, compact substations and cost-sensitive projects

Power transformers, critical substations, smart grids and data center power infrastructure

Measurement Cycle

1 hour optical cycle

Consumables

No carrier gas or calibration gas

Warranty

3-year standard warranty

5-year standard warranty

Technical Specifications

Core HZ-DGA-900 specifications

Essential parameters for online dissolved gas analysis, transformer condition monitoring, moisture measurement, communication and field installation.

Product Type

Online DGA monitoring system

Measurement Method

Photoacoustic spectroscopy + photonic spectroscopy

Measured Parameters

H₂, CH₄, C₂H₆, C₂H₄, C₂H₂, CO, CO₂, O₂ and H₂O

Oil Sampling

Vacuum gas extraction

Measurement Cycle

1 hour

Repeatability

±3%

Calculated Parameters

Total hydrocarbons, N₂, TDCG and rate of change

Consumables

No carrier gas or calibration gas required

Transformer Liquid Type

Mineral oil or ester liquids

Communication

RS485 / Modbus RTU; Modbus TCP available by configuration

Relay Output

NO / NC

Power Supply

220 V AC 50 Hz; 110 V AC 60 Hz optional

Operating Temperature

-40℃ to 70℃

Protection

IP55; IP56 / IP66 customization available by configuration

Dimensions

568 × 391.2 × 785.4 mm

Weight

85 kg

Note: Protection level, Modbus TCP, alarm input, flange configuration and cable length should be confirmed according to the selected configuration and site requirements.

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Applications

Where online DGA is used

HZ-DGA-900 is designed for online transformer condition monitoring where operators need continuous dissolved gas analysis, moisture measurement and early fault diagnosis without carrier gas or calibration gas consumables.

Transformer

Power Transformer Monitoring

Monitor dissolved fault gases and moisture in transformer oil to identify insulation degradation, overheating, arcing and early fault risks.

Power Grid

Substation Asset Health

Support online DGA monitoring for substations, grid transformers and critical electrical assets with 1-hour measurement cycles.

Data Center

Critical Power Reliability

Monitor transformer health in data center power infrastructure to reduce unexpected electrical failures and improve continuity planning.

Smart Grid

Digital Transformer Monitoring

Integrate DGA data, TDCG and gas rate-of-change trends into smart grid monitoring platforms through Modbus communication.

Renewable Energy

Renewable Substations

Apply online DGA monitoring to wind, solar and energy storage grid-connection transformers using mineral oil or ester liquids.

Product Family

Online DGA Monitoring

Compare HZ-DGA-900 with other transformer monitoring products for dissolved gas analysis, moisture monitoring and fault diagnosis.

Related Transformer Monitoring Products

For online monitoring, we provide acoustic voiceprint and DTS monitoring as well.

HZ-DGA-900 Online DGA Monitoring System FAQ

Common questions about online dissolved gas analysis, transformer fault diagnosis, 9-gas monitoring, moisture measurement and maintenance-free DGA operation.

What is HZ-DGA-900 used for?

HZ-DGA-900 is used for online transformer condition monitoring. It measures dissolved fault gases and moisture in transformer oil to support early fault detection, insulation assessment and asset health monitoring.

Which gases does HZ-DGA-900 measure?

HZ-DGA-900 measures hydrogen, methane, ethane, ethylene, acetylene, carbon monoxide, carbon dioxide, oxygen and moisture.

Does HZ-DGA-900 need carrier gas or calibration gas?

No. HZ-DGA-900 is designed for maintenance-free operation without carrier gas or calibration gas consumables.

What is the measurement cycle?

The standard measurement cycle is 1 hour for optical measurement.

What transformer liquids are supported?

HZ-DGA-900 supports mineral oil and ester liquids, including synthetic ester transformer liquids.

Which communication protocols are supported?

HZ-DGA-900 supports Modbus RTU through RS485, and Modbus TCP can be supported according to configuration.

My DGA technical article

What makes our DGA different?

Mar 31,2026

Why PAS DGA is suitable than GC for online monitoring

After decades of development, online DGA monitoring has evolved from simple single‑gas hydrogen detection to a landscape with multiple coexisting technologies. This article systematically reviews the principles, characteristics, and application scenarios of the main DGA technologies – gas chromatography, infrared spectroscopy, photoacoustic spectroscopy, and others – to help readers select the most suitable technical solution for their needs.

Mar 31,2026

What is Dissolved Gas Analysis (DGA): The “Blood Test” for Power Transformers

Dissolved Gas Analysis is the cornerstone of transformer health monitoring. A complete DGA strategy considers not only the nine fault gases but also moisture content, which plays a critical role in insulation integrity. Moreover, the monitoring approach should be tailored to the specific transformer — from single‑gas hydrogen monitors for distribution transformers to full 9‑gas plus moisture systems for critical transmission assets.

Mar 31,2026

Only Hydrogen Monitoring Is Not Enough: The Hidden Challenge of Steel-Origin Hydrogen in Transformers

Hydrogen (H₂) is widely recognized as a sensitive indicator of many transformer faults. It is generated early in partial discharge, corona, and low-energy arcing events, making it a popular choice for single-gas monitoring systems. For many utilities, a hydrogen monitor offers an affordable entry point into online transformer condition assessment.

Plan your online transformer monitoring system.

Tell us your transformer type, oil type, monitoring target, communication requirements and installation environment. HERTZINNO will help you choose the right online DGA monitoring configuration.

Request DGA Solution

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Contact Us: Greenland Mtown, No. 515, Huanke Road, Pudong District, Shanghai, China; info@hertzinno.com

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Online DGA Monitoring Systems

Online DGA for Transformer Oil Analysis

9 Gases + Moisture

1-Hour Cycle

No Consumables

-40℃ to 70℃

Detect transformer faults before they become failures.

Early Fault Warning

Continuous Asset Health

Moisture & Insulation Risk

Data-driven Maintenance

Advanced optical DGA without gas consumables.

Online dissolved gas analysis for transformer health monitoring.

01

02

03

04

Choose the right online DGA model

HZ-DGA-500

HZ-DGA-900

Core HZ-DGA-900 specifications

Download

Where online DGA is used

Power Transformer Monitoring

Substation Asset Health

Critical Power Reliability

Digital Transformer Monitoring

Renewable Substations

Online DGA Monitoring

Related Transformer Monitoring Products

HZ-FA-8

HZ-DTS-1004

Online Acoustic Camera

HZ-DGA-900 Online DGA Monitoring System FAQ

What is HZ-DGA-900 used for?

Which gases does HZ-DGA-900 measure?

Does HZ-DGA-900 need carrier gas or calibration gas?

What is the measurement cycle?

What transformer liquids are supported?

Which communication protocols are supported?

My DGA technical article

Why PAS DGA is suitable than GC for online monitoring

What is Dissolved Gas Analysis (DGA): The “Blood Test” for Power Transformers

Only Hydrogen Monitoring Is Not Enough: The Hidden Challenge of Steel-Origin Hydrogen in Transformers

Plan your online transformer monitoring system.