Tisch ZA-737-250 Zero Air Generator
| Brand | Tisch |
|---|---|
| Origin | USA |
| Model | ZA-737-250 |
| Zero Air Purity | <1 ppb (O₃, CH₄, hydrocarbons, NO/NOₓ, H₂S, SO₂, COS, CO, CO₂, SF₆, fluorocarbons) |
| Flow Rate | 250 L/min |
| Output Pressure | 80 psi |
| Dew Point | −50 °C |
| Flow Measurement Accuracy | ±1 L/min |
Overview
The Tisch ZA-737-250 Zero Air Generator is an engineered solution for laboratories and ambient air monitoring stations requiring ultra-pure, contaminant-free air as a calibration baseline, instrument purge gas, or reference matrix for trace-level gas analysis. Designed and manufactured in the United States, this generator employs a multi-stage purification architecture—comprising catalytic oxidation, high-efficiency particulate filtration, and dual-bed molecular sieve adsorption—to remove reactive and condensable species from compressed air feedstock. It delivers zero air compliant with EPA Method TO-14A, ASTM D6196, and ISO 8573-1 Class 1:1:1 for gaseous contaminants, ensuring traceability and metrological integrity in regulatory-grade environmental testing. Unlike bottled zero air—which introduces variability due to residual impurities, pressure decay, and logistical handling—the ZA-737-250 provides continuous, on-demand generation with stable flow and consistent purity, eliminating cylinder changeover downtime and reducing long-term operational risk.
Key Features
- Ultra-low contaminant output: <1 ppb total hydrocarbons (THC), ozone, nitrogen oxides (NO/NOₓ), sulfur compounds (H₂S, SO₂, COS), carbon monoxide, carbon dioxide, SF₆, and fluorocarbons—verified per EPA Protocol Gas Certification requirements.
- High-capacity flow delivery: Stable 250 L/min output at 80 psi, suitable for multi-instrument manifold distribution or high-flow analyzers such as chemiluminescence NOₓ analyzers and UV photometric ozone monitors.
- Dew point control: Integrated refrigerated dryer and desiccant stage achieve −50 °C dew point, preventing condensation in sensitive optical paths and electrochemical sensors.
- Real-time flow assurance: Precision rotameter or optional digital LED flowmeter with ±1 L/min measurement accuracy; calibrated traceable to NIST standards.
- Robust mechanical architecture: All-welded stainless-steel housings, redundant pressure relief valves, and ASME-certified pressure vessels ensure compliance with OSHA 1910.169 and local compressed gas safety codes.
- Flexible configuration: Available in benchtop or rack-mount form factor; compatible with standard 1/4″ NPT inlet and outlet ports; supports integration into automated air quality monitoring systems (AQMS) via analog 4–20 mA or digital RS-485 interface (optional).
Sample Compatibility & Compliance
The ZA-737-250 is validated for use with EPA-certified ambient air analyzers—including Thermo Fisher Scientific 42i/43i series, Teledyne API 200/400 series, and Horiba APNA-370—as well as FTIR, GC-MS, and PTR-TOF instruments requiring inert carrier or purge gas. Its output meets stringent specifications referenced in U.S. EPA 40 CFR Part 53 (for PM and gas monitor certification), ISO 12039 (for CO analyzers), and EN 14625 (for ozone reference generators). The system supports GLP/GMP environments through documented IQ/OQ protocols and is routinely deployed in U.S. EPA Regional Laboratories, state air agencies (e.g., CA ARB, NY DEC), federal research facilities (e.g., NOAA ESRL, NASA GISS), and academic atmospheric chemistry labs worldwide.
Software & Data Management
While the ZA-737-250 operates as a standalone hardware platform, its analog output (0–5 VDC or 4–20 mA) enables seamless integration into facility-wide SCADA or LIMS platforms. Optional data logging modules record real-time pressure, flow, and temperature parameters with timestamped CSV export for audit-ready records. For regulated environments, the system supports 21 CFR Part 11-compliant electronic signatures when paired with validated third-party software (e.g., LabArchives, Empower). Calibration certificates—including flow meter and pressure transducer calibrations—are supplied with NIST-traceable documentation and annual recalibration services are available through authorized Tisch service centers.
Applications
- Ambient air quality monitoring networks requiring certified zero air for analyzer span/zero checks per EPA 40 CFR Part 58 Appendix A.
- Calibration gas blending systems where ultra-pure diluent air is critical for generating ppb-level standard mixtures.
- Indoor air quality (IAQ) and cleanroom validation, particularly where VOC background interference must be eliminated.
- Research applications in atmospheric chemistry, including OH radical kinetics studies and chamber-based oxidation experiments.
- Reference laboratory accreditation (ISO/IEC 17025) requiring documented uncertainty budgets for zero gas purity and flow stability.
FAQ
What feed air quality is required for optimal operation?
Compressed air input must meet ISO 8573-1 Class 3:3:3 (oil-free, ≤5 µm particles, dew point ≤3 °C), typically achieved using a refrigerated dryer and coalescing filter upstream of the generator.
Can the ZA-737-250 be used for calibration of ozone monitors requiring UV-absorption zero air?
Yes—the catalytic converter and activated carbon stages eliminate ozone precursors and residual ozone to <0.5 ppb, satisfying EPA TO-14A and EN 14625 zero air specifications for UV photometry.
Is routine maintenance required, and what is the recommended service interval?
Catalyst and adsorbent beds require replacement every 12–18 months depending on feed air quality and daily runtime; full preventive maintenance is advised annually per Tisch Technical Bulletin TB-737-M1.
Does the unit comply with electrical safety standards for laboratory use?
Yes—it is UL 61010-1 listed and CE-marked for Class I, Division 2 hazardous locations where applicable.
Can output flow be modulated dynamically during operation?
Yes—via integrated needle valve or optional mass flow controller (MFC) upgrade, enabling programmable ramping and closed-loop flow regulation synchronized with analyzer demand cycles.
