Chapter 1 Helium Supply Chain Crisis

1.1 Middle East Geopolitical Shock and Qatar Facility Damage

In March 2026, Middle East geopolitical conflict escalated dramatically. Ras Laffan Industrial City in Qatar — the world's second-largest helium production base — suffered missile strikes on March 2 and March 18–19, severely damaging LNG and helium extraction, purification, and filling facilities. Simultaneously, shipping through the Strait of Hormuz was disrupted, placing approximately 30% of global maritime helium transport channels at risk of interruption.

Qatar holds a central position in the global helium supply landscape. According to U.S. Geological Survey (USGS) 2026 Mineral Commodity Summaries, Qatar's helium production accounts for approximately 30%–39% of total global supply, together with the United States' 40%–45% forming the dual-pillar structure of global helium supply[6]. The damage to Ras Laffan means approximately one-third of global helium supply has exited the market for the foreseeable future.

QatarEnergy has publicly confirmed that repair timelines for damaged facilities are estimated at 3–5 years[7]. Given the complexity of the current geopolitical situation and the risk of subsequent attacks, actual repair timelines may extend further.

1.2 Global Helium Supply-Demand Dynamics

The supply chain shock rapidly transmitted to pricing. Industrial-grade helium (99.99% purity) CIF China prices surged from 50–70 CNY/m³ in 2025 to 300–400 CNY/m³ by April 2026, a 5–10× increase.

2026Key Indicators of the Annual Helium Crisis

Indicators	Pre-Crisis（2025Year）	Post-Crisis（2026Year4）	Change Magnitude
Industrial Grade Helium Price	50-70 RMB/m³	300-400 RMB/m³	↑ 5-10×
Qatar Global Supply Share	30%-39%	Approaching0（Facility Damaged）	Structural Supply Disruption
Estimated Facility Repair Cycle	—	3-5Year	Medium-Long Term Impact
China's Helium External Dependence	~90%	~90%（Source Blocked）	Structural Vulnerability Exposed

1.3 China's Structural Helium Vulnerability

China's helium consumption import dependency approaches 90%, with approximately 54%–66% from Qatar imports[8]。2026Crisis，This structural vulnerability was fully exposed: even willing to bear high prices, stable quota supply cannot be guaranteed. Some semiconductor manufacturers have received 2-6 week inventory warnings; if supply disruption continues, advanced process lines face shutdown risk.。

Although domestic helium resource development has begun, production capacity is far from sufficient to support national industrial demand. In this context, "reducing helium consumption per detection" has escalated from a cost optimization option to an industry survival option. Switching leak detection processes from 100% pure helium to 1%-20% low-concentration helium mixture means equivalent helium imports can support 5-to-100-fold industrial detection demand — an industry average 10-fold reduction (to 10%) is entirely without problem — this is a "demand compression" strategy implemented on the demand side.。

Chapter 2 Physical First Principles: Equivalent Aperture Comparison

2.1 Three Cognitive Postures on Helium-Based Leak Detection

In <The Three-Body Problem>, when the cosmic microwave background radiation begins to "flicker," Wang Miao feels that "physics no longer exists." Those once-unshakable laws — conservation of energy, thermodynamics, quantum mechanics — seem arbitrarily broken. The reader shares Wang Miao's panic: if even physical laws are unreliable, what can humanity depend on?

But as the story progresses, the truth becomes clear: the flicker is not supernatural — it is the result of Trisolaran "sophons" interfering with human scientific experiments. Physics never disappeared; what disappeared was humanity's ability to recognize physical laws.

The leak detection industry is in a similar cognitive fog. Three fundamentally different cognitive postures exist within the industry:

Comparison of Three Cognitive Postures in the Leak Detection Industry

Posture	Representative Groups	Mental State	Core Problem
Pure-Helium Guardians	Foreign-funded major manufacturers, military production lines, some quality-control-rigorous leading enterprises	"Pure helium is the only standard; any concentration reduction means risk"	Belief not fully validated
Forced-Reduction Pragmatists	Cost-sensitive manufacturers already using 80% He, 60% He, or lower concentrations	"No choice, cost pressure is too great; precision must be compromised"	Belief still in pure helium — wallet simply doesn't permit it
Three-Piece Verification Camp	Pioneering enterprises that understand the essence of this protocol	"Three-Piece VerificationPass = System Reliable，with ConcentrationNoneRelevant"	Correct understanding; needs wider adoption

The group most deserving of attention is Category 2 — the Forced-Reduction Pragmatists. Due to cost pressures, these manufacturers have already reduced helium concentration from 100% to 80%, 60%, or even lower. But they have done something "physically honest" while "belief hasn't caught up": concentration was reduced, but their minds still believe pure helium is more reliable. They feel uneasy, viewing this as a "temporary expedient," planning to return to pure helium once prices subside.

This is "reducing concentration without reducing belief" — deep down, still believing in pure helium. Their unease comes from "lack of validation," not from "concentration reduction."

For Decades，Three"Iron Rules"Considered Unshakable by the Industry：

Instrument reading = physical reality — the 2.3×10⁻⁵ mbar·L/s displayed by the leak detector is regarded as an intrinsic property of the workpiece.

1. Pure helium = only reliable condition: any concentration reduction necessarily leads to precision degradation

Absolute accuracy = core value — the quality of the system depends on how small a number it can measure.

These Three"Iron Rules"are as unshakeable as Wang Miao's "cosmic flicker." In 2026, helium prices surged 5-10×, and many practitioners felt that "leak detection technology no longer exists" — without pure helium, how can testing continue?？

But the truth is equally simple: the notion that "pure helium is irreplaceable" is not a physical law, but an industry convention and path dependency formed under decades of cheap helium supply. Once the physical first principles of leak detection are understood, all "mysterious iron laws" become engineering common sense. More crucially — pure helium itself cannot guarantee detection reliability.

2.2 Physical Reality: The Unchanging Equivalent Leak Aperture

Leak RateQis physically a function of gas species, pressure differential, temperature, and flow regime (molecular/viscous/transitional), not an intrinsic property of the leak channel. According to gas kinetic theory.：

where C is the conductance (related to aperture geometry), ΔP is the pressure differential, T is temperature, M is the gas molar mass, γ is the specific heat ratio, and Kn is the Knudsen number.For the same workpiece, when the test gas switches from 100% helium to 1% helium/nitrogen mixture, the only things that change are the average molar mass and effective partial pressure of the gas mixture — the leak aperture itself remains completely unchanged.

2.3 Four-Layer Framework: From Physical Reality to Instrument Reading

To help understand the relationships among Layers in leak detection, we propose the following four-layer framework:

Four-layer cognitive framework of leak detection — Industry Misconception is treating Layer 4 (Reading) as Layer 1 (Physical Reality).

Four-Layer Framework for Airtightness Detection

Layer	Content	Mutable?	Industry Misconception
Physical Reality	Equivalent leak aperture d₀ on the workpiece	Immutable	Neglected
Purpose	Determine d > d₀ (NG) or d < d₀ (OK)	Immutable	Distorted into "precise measurement"
Means	Tracer gas: 100% He / 1% He / Air / N₂	Replaceable	Belief that "only pure helium works"
Reading	Instrument display in mbar·L/s	Varies with means	Mistaking numbers for physical reality

The industry's core misconception lies in treating Layer 4 (Reading) as Layer 1 (Physical Reality), and treating one option in Layer 3 (100% He) as the only option. Once the problem is examined from the height of the four-layer framework, the myth of "pure helium is irreplaceable" collapses of its own accord.

2.4 The Binary Nature of Production-Line Leak Testing

The ultimate output of production-line helium leak testing has only two possibilities: Pass or Fail. As long as the system can stably answer two questions, its mission is accomplished:

• The Leak Path of This Workpiece ≤ d₀ ？（OK）
• The Leak Path of This Workpiece > d₀ ？（NG）

This "binary judgment" nature determines that the core requirement of production-line leak testing is consistency of judgment, not absolute accuracy.When the cognitive framework switches from "measuring absolute leak rate" to "comparing leak channel size," the necessity argument for pure helium conditions loses its physical foundation.

2.5 Air Leak Testers Have Already Proven: Non-Helium Works

A critical but long-ignored fact: Air Leak Testers and N₂ leak testers are already widely used in industry — they use no helium at all, yet reliably determine Pass/Fail.

Air Leak Testers use compressed air (~78% N₂, 21% O₂, 0.9% Ar, ~5 ppm He) as the test medium, measuring leaks via pressure decay or mass flow meters, outputting Pa·L/s or sccm — no helium, no mass spectrometer, yet reliable operation.

What does this demonstrate? It demonstrates that the industry has in fact already accepted that "non-helium gases can also compare apertures", but has not made this understanding explicit in the helium leak detection context.From air leak testing → low-concentration helium leak testing → pure helium leak testing, this is a continuous spectrum, not a black-and-white boundary.

2.6 The Pure-Helium Myth: Concentration Anxiety vs. Reliability Anxiety

This section is one of the most important cognitive upgrades in this white paper. We need to thoroughly dismantle a deeply rooted Industry Misconception:

Under Pure Helium Conditions，the Following Problemswill automatically disappear. Not a single one.

Traditional belief holds: higher helium purity → stronger signal → higher SNR → more reliable detection. But this reasoning chain breaks at the "SNR → reliability" step.。

Under 100% pure helium conditions, the following problems can fully exist:

Factors That Can Still Cause Unreliable Detection Under Pure Helium Conditions

Problem Source	Specific Manifestation	Impact on Detection Reliability
Instrument Drift	Mass spectrometer filament aging causing daily sensitivity decline; electronics zero-point drift; vacuum pump performance degradation	Yesterday's calibration ≠ today's response; threshold may no longer match actual sensitivity
Ambient Helium Contamination	Large-leak workpieces in pure helium testing cause ambient background to spike from 2 ppm to 50+ ppm, lasting for hours	Subsequent workpieces are measured as "signal + 50 ppm noise," potentially misclassifying OK parts as NG
Unknown Calibration Status	Reference leak uncertified for six months after purchase; temperature changes causing leak drift; micro-leaks at sealing surfaces	Q₀ itself is drifting; all judgments based on it are "flying blind"
Operational Variables	Inconsistent fixture sealing; operator technique variations; helium residue from preceding workpieces	Even at 100% He, operational variables can cause ±30% reading fluctuation for the same part

This means: Pure helium + no daily three-piece validation = reliability unknown. The system may work today and fail tomorrow, but you'll never know — because you never validate.

Forced Helium Reduction80%/60%Manufacturers：Your Anxiety Root Cause Is Not Concentration

To manufacturers who have already reduced to 80% He, 60% He, we say:

This is the cognitive framework shift: from "concentration anxiety" to "validation anxiety." Concentration anxiety has no solution (helium prices are beyond your control), while validation anxiety has a solution (three-piece protocol, a few minutes per day).

Comparison of Two Production Lines：Who Is Truly Reliable？

Reliability Comparison of Two Production Lines

Production Line Type	Helium Concentration	Three-Piece Verification	True Reliability
AProduction Line：Never Verify	100% He	None	Unknown——May Be Good，May Be Bad，NoneBe Judged
BProduction Line：Three-Piece Verification	80% He	Per Shift	Confirm Reliable——GR&R≤15%，Three-Zone Separation
CProduction Line：Three-Piece Verification	1% He	Per Shift	Confirm Reliable——andBProduction Line Equivalent

This comparison reveals a counterintuitive fact: Line B (80% He + three-piece validation) is more reliable than Line A (100% He + no validation). Because Line B confirms the system is in control daily, while Line A merely "pretends" the system is in control.

This is where this protocol is truly disruptive — not saying "low concentration can barely work," but saying: whether you currently use 100%, 80%, 60% or plan to reduce further, the first thing to do is establish a daily three-piece validation system. Only with it can you truly know whether your system is reliable.

Chapter 3 Equivalent Aperture Comparative Method

This chapter is the technical core of the white paper. Having established "equivalent aperture comparison" as the first principle, we must answer an engineering question: how to reliably implement this comparison on an actual production line? The answer is the three-piece protocol (Qₐ+OK+NG) validation system and the concentration reduction iteration method.

But it must be emphasized again: the three-piece protocol is not an adjunct to helium reduction. Even if you have no intention of reducing helium, the three-piece protocol remains the best practice for ensuring detection reliability. Helium reduction is simply the natural extension of the three-piece protocol — since validation is performed daily anyway, why not also find the minimum viable concentration?

3.1 Two Dangerous Modes: Blind Faith in Instruments vs. Forced Helium Reduction

This Is What the Helium Leak Detection Process Looks Like in Most Factories Today：

Startup → Instrument Auto Zero → Place Workpiece → Readings < Threshold? → Pass/Fail

This Process Has a Fundamental Flaw：

What does instrument "zeroing" actually zero? Vacuum background, not system sensitivity. Filament aging and electronics drift go undetected.

Where does the threshold come from? Factory defaults or engineer experience values may not match the current system state.

Is the instrument accurate today? Without validation means, systematic drift leads to batch false judgment.

Is the instrument accurate today? Without validation means, systematic drift leads to batch false judgment.

Traditional Pure Helium Detection's"Blind Faith in Instruments"Mode Problem Analysis

Problems	Specific Manifestation	Consequences
OKWill the Part Be Misjudged？	Never Tested KnownOKPiece	False Inspection RiskNoneBe Quantified

This is like a scale: before weighing each day, not testing with a standard weight, just starting to weigh. Was it accurate yesterday? Is it accurate today? Unknown. Even more terrifying — you're not even sure it was accurate yesterday.

Mode 2: "Forced Helium Reduction" — Physically Honest, Belief Hasn't Caught Up

The second dangerous mode is the forced-reduction pragmatists. Due to cost pressures, these manufacturers have already reduced helium concentration to 80%, 60%, or even lower. But their psychological state is:

"I know 80% He is definitely not as accurate as 100% He, but costs are unbearable. Make do for now, return to pure helium when prices subside."

The essence of this mindset: concentration was reduced, but belief was not. Deep down, still believing pure helium is more reliable, just "forced to compromise."

But the question is — if 80% He is really "inferior" to 100% He, how do you know by how much? 10%? 50%? Or actually no difference? You have no way of knowing, because:

• Noin80%HeConditionsmeasured underThree-Piece Verification——Don't Know If the System Is Stable
• Noin80%HeMeasured Known Under ConditionsNGPiece——Don't Know Missed Detection Rate
• Noin80%HeMeasured Known Under ConditionsOKPiece——Don't Know False Inspection Rate

You haven't even performed three-piece validation under 100% He conditions — you have no idea what the "pure helium baseline" looks like.

So your "80% He is definitely inferior to 100% He" is merely an untested assumption — like the "pure helium belief," it comes from path dependency, not from empirical validation.

3.2 Three-Piece Protocol (Q₀+OK+NG): The Gold Standard

The three-piece protocol is not an adjunct to helium reduction, but the best practice leak detection should have always followed. Whether using 100% He or 1% He, whether reducing helium or not, the three-piece protocol is the correct way to ensure detection reliability.

Three-Piece Verification Is the Foundation of Airtightness Detection"Daily Scale Calibration"：

Three-Piece Analogy：Daily Scale Calibration

Three-Piece System	Role	Analogy：Scale Calibration
Q₀	Confirm Instrument"Just Barely Unqualified"Response	1kgStandard Weight——Scale Shows1kg？
OKPiece	Confirm"Qualified Parts Will Not Be Misjudged as Unqualified"	0.5kgWeight——Scale Will Not Show1.2kg？
NGPiece	Confirm"Unqualified Parts Will Definitely Be Detected"	2kgWeight——Scale Will Not Show0.8kg？

At the start of each day/shift, run all three pieces — this is the correct way to perform leak detection. Whether using 100% He or 1% He, the three-piece protocol should become standard procedure.

3.3 Feasibility and Core Conditions

Three-Piece VerificationPass、System Available WhenCore Conditions：

When both conditions are simultaneously satisfied, the system works normally — regardless of whether 100% He, 1% He, or air is used, as long as these two conditions are met. This is the engineering expression of "sufficient discrimination means feasibility."

The separation ratio (measured $S_{NG}/S_{OK}$ reading ratio) is a natural consequence of the two conditions, not an independent constraint.With the conventional selection of OK=(1/3–1/2)Qₐ and NG=(2–3)Qₐ, even at SNR as low as 3, the separation ratio is typically 2–5, well above the statistical safety threshold.GR&R ≤ 15% ensures within-band variation (±15%) is far smaller than between-band separation; no "gray zone" exists between bands.

Taking battery shell case as example (Qₐ = 5×10⁻⁵ mbar·L/s @ 2 bar He into vacuum, OK=0.5Qₐ, NG=2Qₐ for illustration only; actual selection can be within (1/3~1/2)Qₐ and (2~3)Qₐ range):

Three-Piece Verification Example

Workpiece	Leak Rate	100% HeReadings	1% HeReadings（Estimate）
OKPiece	2.5×10⁻⁵（0.5Q₀）	~50 a.u.	~0.5 a.u.
Q₀	5×10⁻⁵	~100 a.u.	~1.0 a.u.
NGPiece	10×10⁻⁵（2Q₀）	~200 a.u.	~2.0 a.u.
Separation Ratio	—	4.0	4.0

Note: readings at 1% He are estimates only (actual values may deviate due to flow-regime nonlinearity), but the separation ratio remains unchanged — this is precisely the core advantage of the three-piece protocol: it does not depend on theoretical calculations, only on empirical validation.

3.4 Concentration Reduction Iteration: Finding MWC

The concentration reduction iteration method is a systematic approach to finding the Minimum Working Concentration (MWC) for a specific part-instrument combination. MWC is not theoretically calculated; it is empirically determined through three-piece validation.

Find MWC (Minimum Working Concentration).

Every workpiece and every instrument can find its own optimal concentration — not theoretically calculated, but empirically determined through three-piece validation. This is the methodological upgrade from "arbitrarily choosing 1%" to "scientifically finding the optimum."

3.5 Note on "Homologous Cancellation"

In versions v1-v3 of this white paper, we used the term "Homologous Cancellation Relative Judgment Method," with the core equation $S/S_{Q_0} = Q/Q_0$, claiming that concentration terms and system coefficients "completely cancel out" in the ratio."。

Through in-depth engineering practice and discussion, we have recognized that this formulation has an issue of excessive idealization:

• Flow Regime Nonlinearity：When the workpiece leak aperture is in the transitional flow regime (Kn ~ 1), reducing He concentration changes the mixture's average molar mass (from 4 to ~28), and conductance no longer strictly follows the √M relationship; signal reduction may deviate from the concentration ratio.

System non-ideality: filament aging, electronics temperature drift, vacuum background fluctuations mean K is not strictly constant.

Concentration non-constant: mixing tank dynamic consumption, piping adsorption/desorption mean C is not strictly constant.

Therefore，v4Version Makes the Following Corrections：

This correction moves the protocol from "theoretical elegance" to "engineering robustness" — not weakening reliability, but enhancing honesty and operability.

3.6 Why Three-Piece Protocol Is Optimal Even at 100% He

This section delivers the final blow to the cognitive framework. We address a key question:

The answer: not only is it necessary, but the three-piece protocol is the optimal solution for ensuring detection reliability even under pure helium conditions.

Pure Helium Cannot Automatically Solve the Following Problems

Many practitioners believe: "I use 100% He, the signal is strongest, environmental interference is minimal, so I don't need the three-piece protocol." This is a dangerous illusion.

Large-leak ambient background spike — pure helium conditions release more helium, causing more severe contamination. Three-piece validation detects background anomalies → extend purge time.

Instrument sensitivity drift — filament aging, electronics temperature drift are unrelated to helium concentration. Qₐ piece reading drift > 15% → immediate alarm, stop for maintenance.

Reference leak self-drift — permeation leak annual decay 1%-5%, unrelated to concentration. Qₐ reading trend monitoring → early detection of leak aging.

Operational variables (fixture, technique) — human factors unrelated to helium concentration. OK/NG piece validation → confirms operational consistency.

Vacuum system micro-leak — joint micro-seepage signal is larger under pure helium. OK piece reading abnormally high → indicates system sealing issue.

Why Three-Piece Verification Is Still Required Under Pure Helium Conditions

Problems	Whether Automatically Solved Under Pure Helium Conditions	How Three-Piece Verification Solves Problems

None of the above problems automatically disappear under pure helium conditions. Not a single one. 100% He only solves the dimension of "signal strength," while detection reliability is a systems engineering problem involving instruments, environment, operations, and standards.

Correct Cognitive Framework：Three-Piece Verification Is Not an Accessory to Helium Reduction

Many manufacturers understand this protocol as a "helium reduction solution" — believing the three-piece protocol serves helium reduction. This is cause-and-effect inversion.

The Correct Logic Is：

This cognitive framework shift is crucial:

Cognitive Framework Comparison

Dimension	Incorrect Framework	Correct Framework
Core Objective	"Reduce helium cost"	"Ensure detection reliability" — cost reduction is a side benefit
Three-Piece Positioning	"Helium reduction adjunct tool"	"Gold standard of leak detection" — applicable at any concentration
Concentration Decision	"How low can we go?"	"Where is the MWC?" — empirically iterate to find optimum
Quality Cognition	"Reducing helium necessarily sacrifices precision"	"Three-Piece VerificationPass = Accuracy Not Affected"

A Thought Experiment

Assume two production lines, both using 100% He.：

• Production LineA：Never Perform Three-Piece Verification，Startup→Zeroing→Direct Detection
• Production LineB：Perform Three-Piece Verification Daily，Confirm Three-Zone Separation Before Starting Work

Three Months Later，Production LineAexperienced batch missed detections — it turned out filament aging had caused 30% sensitivity decline, but no one noticed because Qₐ validation had never been performed. Line B detected Qₐ reading decline of 18% on the third day, immediately replaced the filament, and had zero missed detections throughout.。

Is the problem helium concentration? No. Both lines use 100% He. The problem is the lack of three-piece validation.

This Thought Experiment Illustrates：The three-piece protocol can equally prevent batch quality incidents under pure helium conditions. It is the "seatbelt" of leak detection — not only needed when driving fast, but needed at any speed.。

Chapter 4 RMI-MTC™ Single-Capillary Reference Leak

4.1 Technical Limitations of Conventional Reference Leaks

The engineering feasibility of the three-piece comparative method is built upon the foundation that the reference leak Qₐ has sufficient precision and stability. Conventional reference leaks have two main approaches, each facing significant bottlenecks.：

Helium Permeation Leak（Helium Permeation Leak）：temperature coefficient as high as 4%/°C — for every 1°C change in ambient temperature, leak rate changes by 4%. Over the 15-35°C temperature fluctuation range typical of industrial sites, leak rate can vary by up to 80%. Additionally, permeation elements are fragile and exhibit 1%-5%/year long-term decay.。

Mechanical capillary leak: aperture is extremely small (micron scale), easily clogged by particulate matter in industrial environments, causing leak rate drift or complete failure.

4.2 RMI-MTC™ Single-Capillary and RMI-CAL Algorithm

RMI-MTC™（Micro-Channel Technology）Standard Leak AdoptsSingle-Channel Capillary Structure，Core Innovation Lies InRMI-CALAlgorithm——this algorithm simultaneously constrains test pressure and leak rate two elements, automatically calculating the capillary length and aperture parameters needed to match the target workpiece's equivalent aperture.。

RMI-MTC™Core Design Features of Single-Channel Capillary Standard Leaks：

Single-channel molecular flow design: capillary dimensions ensure molecular flow state (Kn > 1), eliminating flow regime change effects.

RMI-CAL algorithm precise matching: simultaneously constrains test pressure and leak rate, simulating workpiece equivalent aperture.

Precision machining stability: high-stability substrate and precision machining process, temperature coefficient as low as 0.1%/°C.

• Machining Precision Control：Tolerance Precision Controlled Within±10%Within

4.3 Performance Metrics and Metrological Traceability

Performance Comparison of Three Types of Standard Leaks

Performance Index	RMI-MTC™Single-Channel Capillary	Helium Permeation Leak	Mechanical Capillary
Tolerance Precision	±10%Within	±15%~±25%	±20%Above
Temperature Coefficient	0.1%/°C	~4%/°C	~1%/°C
Pressure Resistance	0~40 MPa	Usually<1 MPa	<5 MPa
Annual Decay Rate	<0.1%	1%~5%	Prone to Clogging and Mutation
Core Innovation	RMI-CALDual-Element Precise Matching	—	—

> **Metrological Traceability Note:** The above performance metrics are based on vendor internal metrology system validation. Users are advised to request traceability certificates to national metrology standards from suppliers during procurement, and to use cross-comparison methods for independent confirmation during production line validation.

Chapter 5 Active Noise Reduction via Low-Concentration Helium

5.1 Causes and Quantification of Ambient Helium Contamination

In traditional pure helium leak detection, ambient helium contamination is a long-neglected problem that seriously affects on-site stability. Under pure helium detection conditions, the following sources continuously release helium into the workshop environment.：

• Workpiece Exhaust Process After Detection Completion（Accounts for Approximately60%-70%）
• Vacuum Fitting、Micro-leakage at Sealing Surface（Accounts for Approx.10%-15%）
• Helium Desorption from Workpiece Surface（Accounts for Approx.10%-20%）
• Helium Emission During Standard Leak Calibration（Accounts for Approx.5%-10%）

These emission sources can cause local workshop helium background concentration to spike from the natural level of 5 ppm to hundreds or even thousands of ppm. After switching to 1% helium mixture, the absolute amount of helium emitted to the environment per test is reduced by 100×, total workshop helium emissions are slashed by 99%, and environmental background returns to natural levels.

5.2 Elimination of Large-Leak Memory Effect

In vacuum helium testing, when a large-leak workpiece enters the detection chamber, large amounts of helium rush into the mass spectrometer, causing the ion source and analyzer to develop a "memory effect" — helium molecules adsorb on metal surfaces and slowly release, causing the baseline of subsequent tests to remain elevated. Traditional solutions require several minutes to over ten minutes of purge waiting time.。

1%Under the mixture protocol, even when a large-leak workpiece occurs, the absolute amount of helium rushing into the mass spectrometer is reduced by two orders of magnitude compared to pure helium conditions. Instrument background recovers to normal levels within seconds, with no need to stop the line and wait.。

5.3 Baseline Stability and Reduced False Alarm Rate

Ambient helium contamination: workshop background far exceeds 5 ppm, environmental noise becomes effective detection floor. Emissions reduced 99%, baseline returns to natural level.

Large-leak memory effect: several minutes to over ten minutes purge waiting → seconds to recover, no need to stop.

Joint micro-seepage: micro-seepage signal is significant under pure helium, may interfere with judgment; micro-seepage signal greatly attenuated, negligible.

Low-Concentration Solution"Active Noise Reduction"Effects Summary

Noise Source	Impact Under Pure Helium Conditions	1%Improvements Under Mixed Gas Conditions
Surface Desorption	Determination of Helium Desorption Interference from Workpiece Surface	desorption total reduced by 99%
Comprehensive False Alarm Rate	Baseline Drift Causes Misjudgment	false alarm rate significantly reduced

The low-concentration solution's "active noise reduction" effect can be qualitatively understood: in SNR = S_signal / S_noise, although the signal numerator decreases proportionally (e.g., from 100% to 1%, signal drops 100×), the noise denominator (ambient helium interference) decreases by a much larger magnitude (environmental emissions reduced by 99%). At sites severely affected by ambient helium contamination, the actual effective SNR may actually increase rather than decrease — this is the "counterintuitive" yet "physically rigorous" core insight of the low-concentration solution.

Chapter 6 Graded Helium Reduction: Three-Piece Validation as Final Authority

Different leak rate ranges correspond to different engineering boundary conditions, requiring differentiated helium concentration strategies. But the core principle of this version remains unchanged: final feasibility is determined solely by three-piece empirical validation; any theoretical analysis is for reference only.

6.1 10⁻⁴ mbar·L/s Range：Very Large Margin Interval

Typical Applications: Automotive air conditioning lines, general refrigeration components, standard industrial seals

This leak rate range is relatively high; even at 1% He, signal has ample margin. Whether conventional takt time (tens of seconds/part) or high-speed lines, three-piece validation can typically pass at 1%-3% He concentration range.

Precision and Reliability Guarantee: At this range, margin is extremely large. When three-piece validation is passed, OK, Qₐ, and NG piece readings are clearly separated (GR&R ≤ 15%). Workpieces judged "Pass" will not be falsely rejected as "Fail," and workpieces judged "Fail" will not be missed as "Pass." Detection precision and reliability are completely identical to conditions at 100% He.

Reference Starting Concentration (Iteration Start): 1%–3%. Final concentration determined by three-piece empirical validation under target takt time conditions.

6.2 10⁻⁵ mbar·L/s Range：Core Application Range

Typical Applications: Battery pack enclosures, refrigeration compressors, moderately demanding industrial seals

This is the most mainstream pass/fail criterion for the new energy vehicle and refrigeration industries, and the core application scenario of this white paper.

Note on Takt Time: Battery pack line speeds vary greatly — from ultra-high-speed lines (20–30 ppm, i.e., 20–30 parts per minute, 3–5 seconds detection time per part) to conventional takt times (tens of seconds per part).What must be made clear: even for the fastest lines (3–5 seconds/part), margin remains substantial. Production lines currently using high-concentration helium (80%-100%) operate normally with instrument background noise at the $10^{-7}$ mbar·L/s level; after helium reduction, background noise will further decrease due to 99% reduction in ambient helium contamination. Conventional takt times (tens of seconds/part) are entirely without problem.。

Precision and Reliability Guarantee: This range is the most economically valuable "sweet spot" of the protocol. When three-piece validation is passed (GR&R ≤ 15% + three-band separation), the system's judgment accuracy for OK and NG parts is identical to conditions at 100% He.

Reference Starting Concentration (Iteration Start): 1%–5%. Final concentration determined by three-piece empirical validation under target takt time conditions.

6.3 10⁻⁶ mbar·L/s Range：Intervals Requiring Appropriate Concentration

Typical Applications: High-seal relays, select medical devices, aerospace critical seals.

This range has relatively low leak rates and requires appropriately higher helium concentration to ensure three-piece validation passes. Start iteration from 10%–20% He, progressively reducing. During concentration reduction iteration, three-piece validation must be performed under target takt time conditions — however fast the production line takt time, use that same integration time for validation.

Precision and Reliability Guarantee: The core logic remains unchanged — passing three-piece validation means the system is reliable. Even using 10%-20% He (still 80%-90% lower cost than 100% He), as long as three bands are separated and GR&R ≤ 15%, detection precision and reliability are identical to 100% He — no false rejects, no missed detections.

Reference Starting Concentration (Iteration Start): 10%-20%. Progressively reduce; when three-band overlap or GR&R > 15%, stop. MWC = previous level concentration.

6.4 Honest Discussion of Flow-Regime Nonlinearity

This white paper adheres to the principle of technical honesty, providing full disclosure on flow-regime issues. But honesty requires the correct framework — the same physical phenomenon carries entirely different significance under the "absolute leak-rate measurement" framework versus the "equivalent aperture comparison" framework.

Under the absolute leak-rate measurement framework, flow-regime nonlinearity is indeed a serious problem. When He concentration drops from 100% to 1%, the mixture's average molar mass changes from 4 to ~28, and the conductance's √M relationship no longer strictly holds in the transitional flow regime. Absolute leak-rate conversion requires complex flow-regime correction.

But under the equivalent aperture comparison framework, this is not a problem.

The reason is simple: Q₀, OK, and NG are measured at the same concentration, on the same equipment, at the same time. The effect of flow-regime changes on all three pieces is uniform and proportional — if the signal compresses to 1/80 instead of 1/100, all three pieces compress synchronously, and the relative discrimination between zones remains unchanged.

The only criterion that matters: Are the three zones separated?

Three-piece verification passes after concentration reduction → GR&R≤15% + clear three-zone separation → system is usable, independent of flow regime.

Three-piece verification fails after concentration reduction → OK overlaps with Q₀ → this is not a "flow-regime problem" but "insufficient discrimination at this concentration" → revert to the previous concentration level. This is an engineering judgment, not flow-regime analysis.

6.5 Common Customer Concerns: Gas Mixture Uniformity and Mixing Accuracy

When promoting helium reduction protocols, customers most frequently raise two concerns: (1) Is the gas mixture uniform inside the cylinder? Particularly for low-concentration mixtures such as 1% He + 99% N₂; (2) Is the mixing accuracy of 1% actually precise? Both questions are essentially manifestations of "absolute accuracy anxiety" — customers are still thinking within the absolute measurement framework when evaluating a comparative method. This section addresses each concern.

Concern 1: Is the Gas Mixture Uniform Inside the Cylinder?

Answer: Necessarily uniform. This is a statistical physics inevitability, not an operational requirement.

Gas molecules at ambient temperature and pressure (inside a 20 MPa cylinder) are in thermal equilibrium, colliding billions of times per second. Although He (molecular weight 4) and N₂ (molecular weight 28) have significantly different masses, they follow the same Maxwell-Boltzmann kinetic energy distribution at the same temperature. Each collision randomizes molecular motion direction, and the system spontaneously approaches thermodynamic equilibrium through diffusion and convection.

Using a 50L cylinder (initially 0.2 MPa He, filled with N₂ to 20 MPa, He mole fraction ~1%) as an example, the density-difference-driven natural convection Rayleigh number reaches ~10¹⁴, far exceeding the convection critical value (Ra~1700). The high-pressure jet turbulence during filling, natural convective mixing after filling, and molecular diffusion for micro-scale homogenization — three mechanisms work synergistically to achieve molecular-level uniformity within hours of standing. Engineering practice conservatively recommends 24 hours.

Concern 2: Is the 1% Mixing Accuracy Actually Precise?

Answer: Precision to exactly 1% does not matter at all. What we need is discrimination, not a concentration label.

The concentration iteration method seeks the Minimum Working Concentration (MWC) — the optimal concentration at which three-piece verification just passes for a given workpiece-equipment-production-line combination. MWC is not "calculated" but found through three-piece empirical iteration.

A cylinder labeled "1% He" may actually contain 0.9% or 1.1% — this has no impact. Three-piece verification does not ask "what is the concentration label?" but rather "at the current actual concentration, are the three zones separated?"

Operationally: The cylinder's labeled concentration serves as a starting reference. Three-piece empirical verification determines whether to continue reducing. Once MWC is systematically found through the concentration iteration method, this concentration is fixed as the production-line standard ratio. Going forward, only supplier batch consistency (±10% is sufficient) is needed — each batch does not need to be precise to exactly 1%.

Chapter 7 Implementation Roadmap

7.1 Phase 1: Three-Piece Baseline (1–2 Weeks)

Objective: Establish Qₐ+OK+NG three-piece baseline readings under pure helium (100%) conditions, confirming system reliability under standard conditions.

Record baseline: record three-piece readings under 100% He conditions as subsequent comparison baseline. Data is fully traceable.

Phase 1 Verification Items and Pass Criteria

Verification Items	Operating Method	Pass Criteria
Q₀Piece Calibration	ConnectionQ₀Standard Leak，Record SignalS_Q₀	Signal Stable，NoneAbnormal Fluctuation
NGParts Detection Verification	Test Leak Rate(2~3)Q₀NGPiece，RecordS_NG	S_NG > S_Q₀，NGParts Can Be Reliably Detected
OKParts Pass Verification	Test Leak Rate(1/3~1/2)Q₀OKPiece，RecordS_OK	S_OK < S_Q₀，OKParts Will Not Be Misjudged
Repeatability Test	Continuous20Three-Piece Cycle Tests	SystemGR&R≤15%

7.2 Phase 2: Concentration Iteration (2–4 Weeks)

Objective: Through concentration reduction iteration, find the MWC (Minimum Working Concentration) for this part-instrument combination.

• from100% HeStart，By50%→20%→10%→5%→2%→1%Gradually Reduce Concentration
• After Each Concentration Reduction，Fully Execute Three-Piece Verification（Q₀→OK→NG）
• Record Three-Piece Readings，ConfirmS_OK < S_Q₀ < S_NG
• When Three Zones Overlap orGR&R>15%Stop When，MWC=Previous Concentration Level
• Recommend Simultaneous Temperature Recording、Humidity and Other Environmental Parameters

7.3 Phase 3: Production Deployment & Monitoring

Target：Full Production Line Rollout with Long-Term Monitoring Mechanism。

• Based onPhase 2DeterminedMWCDeploy Production Line
• Standard Procedure at the Start of Each Shift：Three-Piece Verification → Pass → Start Detecting Workpieces
• Re-check at the End of Each Shift：Three-Piece Verification Again，Confirm Drift<±15%
• EstablishSPCChart，Continuously Monitor Three-Piece Reading Trends
• Establish Regular Review Mechanism（Weekly），Analyze Three-Piece Data and Optimize

7.4 Sniffer & Accumulation Method Implementation

This protocol is most rigorously validated for the Vacuum Method, but the Sniffer Method and Accumulation Method are equally feasible, each with key points:

Chapter 8 Economic Analysis

Taking battery pack helium leak detection line as an example (5–6 million units/year), based on actual industry operating data:

Battery Pack Helium Detection Production Line（Annual Production500-600Ten Thousand Units）Cost Comparison

Cost Items	Pure Helium Method（100%He）	Low-Concentration Helium Method（10% + Three-Piece System）	Illustration
Helium consumption	~300 cylinders/year	~30 cylinders/year	50 L × 20 MPa specification, 17,000–20,000 parts/cylinder
Helium procurement cost	~900,000 CNY/year	~90,000 CNY/year	3,000 CNY/cylinder
Three-piece protocol investment	None	10,000–30,000 CNY (one-time)	Qₐ reference leak + OK/NG test artifact fabrication
Gas mixing equipment	—	Mixing tank and accessories (depreciation)	Cost far lower than recovery systems
Annual Helium Cost Savings	—	~800,000 CNY/year	~90% reduction

More Important Are the Hidden Benefits：

Detection reliability improvement: three-piece daily validation eliminates systematic drift, reducing batch false judgment rate by over 50%.

Production line downtime reduction: large-leak clear time from several minutes to several seconds; effective takt time improvement 3%-8%.

Data traceability: every shift has three-piece calibration records, quality audit has basis, satisfying IATF 16949 and other system requirements.

Premixed gas supply risk: need to confirm mixed gas supplier stability; recommend selecting 2+ suppliers.

Hidden Benefits and Risk Assessment

Benefits/Risk Items	Description	Quantitative Estimate
Supply Chain Risk Hedging	Low Consumption=High-Assurance Flexibility	Avoid Supply Disruption and Production Losses

Chapter 9 Strategic Significance

9.1 Cost Reduction+Efficiency Gain：Dual Transition

The core strategic value of this solution lies in achieving the dual leap of "cost reduction" and "reliability enhancement":

• Cost Reduction：Helium Cost Reduction80%-90%，Battery Pack Production Line Annual Savings of Approx.80Ten Thousand RMB

Reliability Enhancement: three-piece daily validation significantly improves detection reliability — no missed detections, no false rejects, data traceable.

These Two Matters Are Not Simply"1+1=2"，But RatherMutually Reinforcing：helium reduction makes three-piece protocol adoption possible (helium cost is no longer a barrier), and the three-piece protocol ensures the reliability of helium reduction (daily validation confirms normal system operation).）。

9.2 Supply Chain Security: From "Begging to Buy" to "Being Begged to Buy"

For the entire industrial helium leak detection industry, reducing helium usage to 1%-20% of original is completely feasible, and an average 10× reduction (to 10%) is entirely without problem. This judgment is based on the following facts:

Ultra-high-speed lines (3-5 seconds/part, battery pack 20-30 ppm): margin remains substantial; background noise further reduced after helium reduction.

• Standard Production Line（Dozens of Seconds/Piece）：Even Moreentirely without problem，1%-5%HeUsually Sufficient
• Precision Production Line（10⁻⁶Order of Magnitude）：10%-20%HeIs Sufficient，Still Lower Than Pure Helium80%-90%

When industrial helium leak detection consumption drops to 10% of original, the helium crisis ceases to exist.This is not "reducing demand," but "reconstructing demand elasticity":

• Equivalent import volumes can support 10×+ industrial detection demand (if average reduction reaches 10%)
• Limited domestic helium production capacity suddenly becomes "sufficient"
• Strategic helium reserve industrial protection period significantly extended
• China's bargaining power in helium negotiations significantly enhanced

This is equivalent to implementing a "demand-side revolution" in the helium supply chain — not increasing supply, but compressing demand to a controllable range.

9.3 from"Catch Up"to"Definition Standard"

When the helium reduction protocol is deployed at scale in Chinese industry, China will become the definer of low-concentration helium leak detection standards. When other countries seek to address helium dependency, they will reference Chinese technical specifications and best practices.

This upgrades from "selling products" to "defining the rules of the game" — selling products earns thousands; defining standards influences the entire industry. At the critical stage when domestic industry shifts from "catching up" to "leading," "defining new standards" may have greater strategic value than "optimizing old metrics."

Chapter 10 Applicability, Risk Boundaries & Disclosures

This white paper adheres to the principle of technical honesty. The following provides full disclosure of the protocol's applicable boundaries and potential risks.

10.1 Applicability of Detection Methods

Typical Applications: Automotive air conditioning lines, general refrigeration components, standard industrial seals.

This leak rate range is relatively high; even at 1% He, signal has ample margin. Whether conventional takt time (tens of seconds/part) or high-speed lines, three-piece validation can typically pass at 1%-3% He concentration range.

Accumulation Method fully validated: accumulation chamber is closed, time control is essentially similar to Vacuum Method.

Sniffer Method feasible but higher threshold: sniff flow rate must be constant (MFC/constant flow pump); reducing He does not reduce noise.

This is the most mainstream pass/fail criterion for the new energy vehicle and refrigeration industries, and the core application scenario of this white paper.

Applicability Assessment of Various Detection Methods

10.2 Temperature Impact

For a 5-6 million battery pack line, annual helium cost is approximately 900,000 CNY; at 10% concentration, only approximately 90,000 CNY is needed, saving approximately 800,000 CNY annually. Missed detection and false reject rates remain unchanged.

Typical Applications: High-seal relays, select medical devices, aerospace critical seals.

Precision and Reliability Guarantee: The core logic remains unchanged — passing three-piece validation means the system is reliable. Even using 10%-20% He (still 80%-90% lower cost than 100% He), as long as three bands are separated and GR&R ≤ 15%, detection precision and reliability are identical to 100% He — no false rejects, no missed detections.

Reference Starting Concentration (Iteration Start): 1%-3%. Final concentration determined by three-piece empirical validation under target takt time conditions.

The "homologous" assumption requires stable helium partial pressure in the mixing tank. Recommended measures: mixing tank volume designed for >200× single consumption; install online concentration monitoring; multi-station lines consider zoned gas supply; select 2+ mixing gas suppliers.

Conclusion: Physics Not Only Exists, but Is Beautiful

Liu Cixin writes at the end of <The Three-Body Problem>: "Physics not only exists, but is beautiful."

When Wang Miao saw the regular flickering of cosmic microwave background radiation through his 3K glasses, he understood: phenomena that seem to break physical laws are in fact precisely deeper physical laws at work. Mystery exists not because laws do not exist, but because our cognition has not yet reached them.

The leak detection industry is undergoing the same cognitive leap.

For decades, "pure helium is irreplaceable" was as unshakeable as the "cosmic flicker." The 2026 helium crisis made many feel that "leak detection technology no longer exists" — without pure helium, how can quality be guaranteed?

But when we return to physical first principles — the essence of leak detection is comparing the size of equivalent leak apertures — everything becomes clear:

• Gases (100% He, 1% He, air, N₂) are merely tracer media, not ends
• Readings (mbar·L/s) are response numbers produced by means, not physical reality
• The Only Constant IsEquivalent leak aperture d₀ on the workpiece
• As long as discrimination is sufficient, any gas concentration can work

More importantly, we have finally understood the true meaning of "reliable":

The three-piece protocol (Qₐ+OK+NG) lets us "calibrate the scale" daily, ensuring system reliability. The concentration reduction iteration method lets us scientifically find the optimal concentration rather than guessing. Combining both achieves the dual leap of cost reduction + reliability enhancement — helium costs drop 80%–90% (saving approximately 800,000 CNY annually for battery pack lines), while detection reliability substantially improves.

This is not only a response to the 80%/60% forced-reduction manufacturers — telling them "your anxiety does not come from concentration, but from lack of validation" — but also a reminder to the entire industry: the pure helium belief should be laid down; three-piece validation should be picked up.

When industrial helium leak detection consumption drops to 10% of original, the helium crisis ceases to exist.This is not only a victory of technology, buta victory of physical first principles——Returning to essence, mystery becomes common sense.。

Physics not only exists, but is beautiful.