Nutech 2203 Precision Static Dilutor

Nutech 2208 Precision Static Dilutor

The Nutech 2208 Precision Static Dilutor is designed for accurate and reproducible preparation of gas standards. It enables automated dilution of high-concentration gas standards into low-level working standards, making it ideal for laboratory calibration and quality control applications.

The system can also be used to dilute high-concentration gas samples to levels within the calibration range of analytical instruments such as GC, GC/MS, or FID-based analyzers.

Static Dilution Method

Static dilution is a well-established method for preparing calibration gas mixtures. In this approach, a known quantity of standard gas and diluent gas is introduced into a fixed-volume chamber at a defined ratio.

The amount of each gas can be determined by pressure differential, volume measurement, or gravimetric methods. The gases are then mixed within a sealed chamber or manifold to produce a homogeneous calibration mixture. Diluent gases typically include zero air or humidified zero air, depending on application requirements.

Application Notes

6 Channels for Standard

Eliminate cross contamination due to share the same channel between different standards

Seperate Channels for Standard and Sample

Eliminate cross contamination due to sample and standard sharing the same channel

Nutech 2208 Precision Static Dilutor Key Features

1. Dedicated Flow Paths to Eliminate Cross-Contamination
Independent standard gas and sample gas ports ensure complete separation of flow paths, fundamentally preventing cross-contamination during both standard preparation and sample dilution.

2. Ultra-High Dilution Capability for Trace-Level Applications
Supports multi-stage dilution with >1,000× primary dilution and >10,000× secondary dilution, enabling accurate preparation of ultra-low concentration standards.

3. Fully Inert-Treated Flow Path for Maximum Stability
All tubing, valves, and wetted surfaces are treated with advanced inert coating technology to minimize adsorption and ensure stable recovery of VOCs, including polar compounds.

4. True Precision Control with MFC + Pressure Sensors
Combines high-precision mass flow controllers (MFC) and pressure sensors to ensure accurate dilution ratios, avoiding the limitations of pressure-only control methods.

5. Multi-Channel Design for Flexible Standard Management
Equipped with 8 channels:

  • 6 for standard gases
  • 1 for dilution gas
  • 1 for secondary standard

Each standard can be assigned to a dedicated channel, enabling efficient multi-component workflows.

6. Integrated Sample Dilution Capability
In addition to standard preparation, the system can dilute high-concentration samples to within the calibration range of analytical instruments.

7. Intelligent Automation with User-Friendly Software
The control software automatically performs:

  • Initial pressure verification
  • Dilution factor calculation based on final pressure input

This significantly simplifies operation and reduces human error.

8. Automatic Leak Detection for Reliable Operation
Built-in leak detection ensures system integrity before dilution, preventing failed preparation and ensuring data reliability.

9. Heated Flow Path to Prevent Condensation and Adsorption
All gas pathways are temperature-controlled to eliminate condensation and reduce compound loss, especially for semi-volatile components.

10. Integrated Purge Function for System Cleanliness
Automated purging and rinsing of flow paths between runs eliminates carryover and ensures high dilution accuracy.

11. Built-in Calibration and Validation Module
Enables routine system verification and performance checks, supporting long-term accuracy and compliance with laboratory QA/QC requirements.

On-site Pictures of 2208 Precision Static Dilutor

Intuitive Software for Method Setup and System Monitoring

Customer Testimonials

The following investigation was conducted to evaluate the efficacy of pairing Restek products with the Nutech 8900DS preconcentrator to meet the five most pertinent criteria of Method TO-15. Results demonstrate that the combination …. easily meet all of the criteria for TO-15 VOC analysis.

Dr. Jason Herrington, Restek Corporation

FAQ

The system supports single-stage dilution up to 1000× and multi-stage dilution up to 10,000×, enabling preparation of trace-level standards down to ppb range.

The dilution accuracy is better than 1%, provided proper calibration and leak-tight conditions are maintained.

Supported gases include:

  • Nitrogen (N₂)
  • Air
  • Helium (He)
  • Hydrogen (H₂)

Gas selection depends on the chosen dilution method (FC or Pressure-based).

  • FC (Flow Control): Uses flow sensors to quantify injected volume
  • P (Pressure Differential): Uses pressure change to calculate gas volume

FC provides direct volumetric control, while P relies on pressure-based calculation.

Yes. The 2208 supports:

  • Standard gas dilution
  • Sample dilution (pressurization-based)
  • Liquid sample vaporization dilution

This enables flexible workflows across calibration and unknown sample preparation.

The system provides 8 channels:

  • 6 standard gas channels
  • 2 dilution-related channels

Each standard gas should use a dedicated channel to avoid contamination.

Reusing a channel for different standards can cause residual contamination (~0.1 ppb level) due to adsorption/desorption in tubing.

Dilution gas should be ≥99.999% purity.
If blank levels are high, a hydrocarbon removal trap is recommended.

Only GC-grade stainless steel or silica-coated tubing should be used.
Copper or plastic tubing can release VOCs, leading to contamination.

The system performs an automatic Leak Check by pressurizing to ~40 psi and monitoring stability.
Leaks directly affect dilution accuracy and must be eliminated before operation.

Recommended pressure range:

  • 30–40 psig for both standard gas and diluent gas

Insufficient pressure will interrupt operation.

  • Temperature: 20–35°C
  • Humidity: <85% RH
  • No strong vibration, magnetic field, or corrosive gases

These conditions ensure measurement stability.

After powering on, the system requires thermal and pressure stabilization to ensure accurate flow and pressure measurement before dilution begins.

The system includes a humidification calculation tool that determines:

  • Water addition volume
  • Final pressure

This prevents condensation inside the canister.

Proper humidification minimizes:

  • Adsorption losses
  • Surface interaction effects

Especially critical for polar VOC compounds.

Prepared gas mixtures should stand for at least 12 hours before analysis to ensure equilibrium.

Yes. The software automatically logs experiments and generates QA/QC reports, including:

  • Dilution parameters
  • Time records
  • Process data

Flow calibration uses a linear segmented model (y = Ax + B) with:

  • Two calibration segments
  • Requirement: R² ≥ 0.999

This ensures high-accuracy flow control.

Failure to close the valve may cause:

  • Pressure buildup in internal lines
  • Long-term sensor damage

Proper shutdown is critical for system longevity.

Yes, but with limitations:

  • Pressure must remain at atmospheric level
  • Risk of compound loss (adsorption/permeation)

Therefore, Summa canisters are preferred for accurate VOC standards.

2208 Predecessor Model – Nutech 2203 Precision Static Dilutor

Nutech 2203 Precision Static Dilutor

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Supported Methods & Standards

Nutech instruments are designed to support a wide range of internationally recognized monitoring methods and standards.

US EPA Method TO-14A/15/15A

Determination of Volatile Organic Compounds (VOCs) in Air Collected in Specially Prepared Canisters and Analyzed by Gas Chromatography–Mass Spectrometry (GC-MS)

US EPA Method 327

Fugitive and Area Source Measurement of Selected Volatile Organic Hazardous Air Pollutants Using Specially Prepared Canisters

US EPA Method OTM-50

Sampling and Analysis of Volatile Fluorinated Compounds from Stationary Sources Using Passivated Stainless Steel Canisters

NIOSH Method 3900

Volatile Organic Compounds, C1 to C10, Canister Method

ASTM D5466-21

Standard Test Method for Determination of Volatile Organic Compounds in Atmospheres (Canister Sampling, Mass Spectrometry Analysis Methodology)

GAW (Global Atmosphere Watch) Report 204

Standard Operating Procedures for Air Sampling in Stainless Steel Canisters for Non-Methane Hydrocarbons Analysis

China HJ 759

Ambient air-Determination of volatile organic compounds- Collected by specially-prepared canisters and analyzed by gas chromatography/mass spectrometry

China HJ 1444

Ambient air－Determination of 10 sulfur compounds－Collected in canisters and analyzed by preconcentration/gas chromatography

Japan National VOCs Analysis Standard (7 Compound with TO-17 and 14 Compound with TO-15)

Manual for Measurement Methods for Monitoring Volatile Organic Compounds (VOC) Concentrations in Ambient Air

Japanese original name: 環境大気中の揮発性有機化合物（VOC）濃度モニタリングに係る測定方法マニュアル

Taiwan NIEA A715.16B

Method for Determination of Volatile Organic Compounds (VOCs) in Air Collected in Canisters and Analyzed by Gas Chromatography/Mass Spectrometry (GC/MS)

Taiwan NIEA A741.12B

Method for Determination of N-Butyl Acetate and Other VOCs in Air Collected in Canisters and Analyzed by GC/MS

Nutech VOCs Analysis & Monitoring Projects

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NIST Using Nutech's 8910 Preconcentrator
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