With the rapid development of AI Data Centers and Battery Energy Storage Systems (BESS), the detection of combustible gases such as hydrogen and carbon monoxide has become an important component of critical facility safety protection. However, international standards not only focus on whether gases can be detected, but also emphasize whether gas concentrations can be accurately, stably, and repetitively measured.
For critical facilities related to personnel safety, asset protection, and business continuity, combustible gas detectors play an important role in triggering alarms, coordinating ventilation, controlling equipment operation, and supporting emergency decision-making. If the on-site gas concentration cannot be accurately reflected, even if the detector can sense the presence of gas, it is difficult to meet the requirements of critical industrial safety applications.
Why do data centers and lithium-ion energy storage systems require 'quantitative measurement' for thermal runaway management?
From Air Quality Index to Quantitative Measurement of Combustible Gases
In the fields of consumer electronics and indoor air quality monitoring, metal oxide semiconductor (MOS/MOX) sensors are commonly used to identify changes in air quality, responses to volatile organic compounds, or abnormal environmental trends. This type of product can output air quality index, relative change value, or comprehensive evaluation results processed by algorithms, but this type of output is not equivalent to the accurate concentration of a certain combustible gas.
The resistance response of MOS sensors may be affected by factors such as target gas, other volatile substances, temperature, humidity, oxygen conditions, material aging, and long-term pollution. In the presence of multiple gases or continuous changes in environmental conditions, the same output signal may correspond to different gas compositions and concentrations. Therefore, MOS schemes that have not been fully calibrated, compensated, and validated for overall performance are often difficult to continuously provide accurate, stable, and traceable ppm or% LFL concentration data in complex industrial environments.
Based on this technological feature, some consumer electronics products present monitoring results in the form of air quality levels, indices, or trend changes, rather than directly displaying specific gas concentrations. For air quality management, it belongs to low-risk application scenarios, which can meet the requirements of status prompts; However, for critical facilities such as energy storage systems and data centers, simply outputting change trends or alarm signals is not sufficient to support safety control based on concentration thresholds.
'Alarm signal' cannot replace 'concentration data'
At present, some MOS/MOX gas detection products on the market for battery thermal runaway monitoring only provide alarm status based on gas change trends and do not provide real-time gas concentration values. In this situation, it is difficult for the owner, insurance company, engineering consultant, and system integrator to independently confirm:
What is the actual gas concentration when the alarm occurs;
Is the alarm set value consistent with the design threshold;
Whether the sensitivity of the sensor has decayed or drifted;
Does the detector still have effective detection capability after long-term operation;
Whether ventilation, interlocking, and fire control are activated under the correct concentration conditions.
Even if the device can generate an alarm signal, it cannot prove the accuracy of its concentration measurement, long-term stability, and reliability of the alarm threshold. For critical security systems, unverifiable alarm logic itself is a very high security risk. More and more regulatory agencies, insurance companies, data center owners, and energy storage system manufacturers are realizing the enormous commercial risks and public safety hazards they pose.
NFPA 855 focuses on verifiable risk control
The current version of NFPA 855 is 2026, which covers safety measures such as fire detection, gas detection, exhaust, and explosion control for energy storage systems.
In the discussion of technical provisions related to reducing the risk of explosion triggered by combustible gas detection, the relevant requirements are based on the percentage of the lower flammable limit as the control basis, such as initiating corresponding protective measures when the gas mixture or single component does not exceed 10% LFL. This type of requirement essentially relies on quantitative measurement of combustible gas concentration, rather than just judging whether the gas signal has changed.
According to NFPA 855 (2026 edition) requirements:
The gas detection system should activate the combustible gas concentration reduction system (CCR) when the combustible gas concentration does not exceed 10% of the lower explosive limit (LFL).
For hydrogen, the threshold is approximately 4000ppm.
For data centers, energy storage systems, petrochemical and hydrogen facilities, combustible gas detection systems not only provide alarm functions, but also need to provide reliable decision-making basis for automatic control systems.
In data centers and energy storage systems, gas concentration data may be directly used for:
Activate the mechanical ventilation system
Control HVAC operation mode
Implement graded alarm system
Implement equipment interlocking control
Support linkage of fire protection system
Provide emergency decision-making basis for operators
These control strategies typically correspond to preset concentration thresholds (such as ppm or% LEL), therefore, only detectors that can accurately reflect the gas concentration on site can ensure that safety strategies are executed according to design intent.
These safety actions are based on accurate and traceable concentration measurements, rather than simply judging whether there is gas or not.
Data center: Accurate concentration measurement supports continuous operation
With the application of technologies such as lithium-ion UPS, backup batteries, and fuel cells, data centers are heavily equipped with hydrogen detection systems.
International engineering design typically sets graded responses based on different concentrations, such as:
Low concentration (500ppm) and multi-stage hydrogen concentration detection alarm strategy
Activate the ventilation system
High concentration alarm
Equipment interlocking or emergency response
If the detector cannot continuously provide accurate concentration data, the system may face two risks:
False Alarm
Resulting in frequent shutdowns, business interruptions, and increased operational costs.
Missed Alarm
Failure to take timely control measures when hazardous gases reach the risk level increases safety risks.
Therefore, data centers are more concerned with long-term stable quantitative measurement capabilities, rather than just the ability to perceive gases.
BESS: Concentration data determines safety strategies
In energy storage systems (BESS), combustible gas detection is not only used to detect thermal runaway, but also plays an important role in initiating safety strategies.
For example:
Activate the exhaust system
Control HVAC
Trigger level one alarm
Activate Level 2 alarm
Support fire linkage
These actions are usually performed based on preset concentration thresholds.
If the detector output cannot accurately reflect the gas concentration on site, it may lead to:
Ventilation starts too early, increasing energy consumption
Ventilation started too late, increasing danger
Alarm point drift
Security policies cannot be executed as designed
Therefore, for BESS, quantitative measurement not only affects alarms, but also directly affects the entire safety control logic.
Moving from "detecting gases" to "measuring gases"
With the rapid development of emerging industries such as AI data centers, energy storage systems, and hydrogen energy, the industry's requirements for gas detectors are changing.
Previously, the focus was on:
Can combustible gases be detected.
What I am more concerned about today is:
Can the concentration of combustible gases be measured accurately and long-term, and support safety control decisions.
This means that gas detectors are not only alarm devices, but also important components of critical facility safety control systems.
ProSense is a gas sensing solution specifically designed for lithium battery scenarios in AI data centers
As an industry leader in the research and manufacturing of advanced gas sensors, ProSense continues to promote technological breakthroughs and international compliance processes in the field of energy storage applications, starting from complex on-site environments.
The hydrogen sensor series models under the company have obtained UL 2075 certification in the United States and CAN/ULC 588 certification in Canada. The working temperature range of the products covers -40 ℃ to 105 ℃, and they have become industry benchmarks in terms of environmental adaptability, long-term stability, resistance to silicon poisoning, and reliability. They have been widely used in energy storage system safety monitoring, AIDC infrastructure, and new energy related scenarios.
Advanced gas sensing solutions include:
Low concentration and multi-level hydrogen detection and system linkage: achieve integration of low concentration (500ppm), 10% LFL (4000ppm), 25% LFL (10000ppm) multi-level concentration hydrogen detection with battery management system (BMS) and safety control strategy.
Anti pollution and anti silicon poisoning design: effectively reduces the chemical coverage of sensitive components by interfering substances such as VOCs and siloxanes, and improves the stability of hydrogen and CO sensors in long-term high pollution environments.
Optimization of high temperature resistance: Meet the continuous testing requirements of energy storage facilities under closed energy storage cabinets and high temperature operating conditions before operation.
Improved lifecycle stability: Extend the effective operating cycle of sensors, reduce the risk of frequent on-site replacement, maintenance, and drift.
About ProSense
ProSense is a high-tech enterprise dedicated to the research and manufacturing of advanced gas sensors, committed to providing high-performance and high reliability sensing solutions for global customers. The company continues to invest in core technology research and development, overcome key pain points in the industry, and continuously lead the development direction of gas sensing technology. With innovative products and excellent quality, ProSense is gradually growing into an important promoter and leader in the global gas safety monitoring field.
ProSense adheres to the full stack self-developed technology route, and has established a kilogram level gas sensor catalyst research and development base and an automated production aging calibration system for millions of gas sensors per year. Its product line covers the fields of toxic and harmful, flammable and explosive, and environmental gas detection; ProSense multiple innovative products have become core sensing components in vertical fields such as smart firefighting, industrial testing, and energy storage safety.
