Graywolf Zephyr XM Differential Pressure and Barometric Pressure Meter

Overview

The Graywolf Zephyr XM is a high-fidelity handheld differential and barometric pressure meter engineered for precision-critical applications in HVAC system commissioning, indoor air quality (IAQ) assessment, cleanroom validation, and containment integrity testing. Its core measurement architecture employs dual piezoresistive MEMS pressure sensors—configured for simultaneous differential (ΔP) and absolute (barometric) pressure acquisition—with real-time auto-zero compensation and seamless auto-ranging across five decades of span (±0.1 Pa to ±10,000 Pa). This enables traceable, low-drift measurements essential for verifying pressure differentials across HEPA filter banks, isolation rooms, fume hoods, and pharmaceutical isolators. Unlike conventional microbarometers relying on single-sensor interpolation, the Zephyr XM’s hardware-based dual-sensor design eliminates range-switching artifacts and ensures consistent resolution and linearity throughout its full dynamic range—critical for meeting ISO 14644-3 Annex B requirements for cleanroom pressure mapping and ASHRAE Guideline 12-2020 protocols for healthcare facility infection control.

Key Features

• Ultra-high-resolution differential pressure measurement down to 0.1 Pa (0.002 inH₂O), switchable among SI and imperial units including mmH₂O, mbar, mmHg, and atm
• Dual-sensor architecture supporting concurrent ΔP and barometric pressure logging with independent calibration traceability
• Auto-zero function executed on-demand or scheduled—compensating for thermal drift and sensor hysteresis without manual intervention
• Integrated data annotation suite: time-stamped audio notes (via front-facing MEMS microphone), text memos, and “event markers” synchronized to measurement streams
• 32 GB embedded flash memory enabling multi-month continuous logging at 1 Hz sampling (exceeding 2.5 million readings), with WolfSafe™ automatic backup to prevent data loss
• 3.5-inch HVGA color touchscreen with glove-compatible touch response and configurable display layouts for trend graphs, numeric readouts, or statistical summaries (min/max/avg)
• Expandable sensor ecosystem supporting Pt100 RTD (−15°C to +70°C, ±0.3°C), K-type thermocouples (−200°C to +1372°C), and optional RH-ASX humidity/temperature probes (0–100% RH, ±2% RH below 80% RH)

Sample Compatibility & Compliance

The Zephyr XM is validated for use with standard pitot tubes (Type S, Prandtl), thermal anemometers (AS-201/202A), and calibrated static pressure probes used in duct traverses per ASHRAE Standard 111 and ISO 5167. Its pressure ports accept ¼″ NPT and push-fit tubing connections compatible with Tygon®, Viton®, and stainless steel capillary lines. All firmware and calibration routines adhere to GLP-aligned documentation standards—including audit-trail-enabled calibration history, user-access controls, and electronic signature support via optional WolfSense® ARG software. The instrument meets EMC Directive 2014/30/EU and carries CE marking for use in EU-regulated environments. While not FDA 21 CFR Part 11–certified out-of-the-box, its data export formats (CSV, PDF, XML) and metadata-rich logging structure facilitate integration into validated QMS platforms compliant with ISO 13485 and GMP Annex 1.

Software & Data Management

Data retrieval and reporting are managed through Graywolf’s WolfSense® desktop application (Windows/macOS), which supports direct USB-C or Wi-Fi sync. Raw datasets include full metadata: sensor ID, calibration date, operator ID, GPS coordinates (when enabled), ambient temperature/humidity, and user-defined project tags. The optional WolfSense® ARG (Advanced Reporting Generator) module enables automated report generation conforming to ISO/IEC 17025 technical record templates—including uncertainty budgets derived from sensor accuracy specifications, environmental correction factors, and statistical confidence intervals. Export options include PDF with embedded trend charts, CSV for statistical process control (SPC) analysis, and XML for LIMS ingestion. All audio annotations are stored as compressed WAV files linked to their corresponding timestamped pressure records.

Applications

• HVAC balancing and TAB (Testing, Adjusting, Balancing) per NEBB Procedural Standards
• Cleanroom classification and pressure cascade verification per ISO 14644-1 and EU GMP Annex 1
• Pharmaceutical isolator and RABS integrity testing (e.g., leak rate calculation via pressure decay method)
• IAQ investigations including building envelope leakage assessment and stack effect quantification
• Laboratory hood face velocity and room pressure differential monitoring per ANSI/AIHA Z9.5
• Industrial ventilation system performance audits per OSHA 1910.142 and ACGIH TLVs

FAQ

Does the Zephyr XM require annual recalibration?
Yes—Graywolf recommends annual factory recalibration against NIST-traceable standards. Field zero-checks can be performed daily using the built-in auto-zero function, but full metrological validation requires certified reference equipment.
Can the Zephyr XM measure airflow volume directly?
No—it measures differential pressure across pitot arrays or orifice plates; volumetric flow (SCFM or ACFM) is calculated internally using user-input duct geometry, temperature, and optional relative humidity compensation when paired with RH-ASX or TRH probes.
Is the device suitable for outdoor barometric pressure logging over extended periods?
Yes—the operating range (−10°C to +50°C, 0–100% RH non-condensing) and sealed enclosure (IP54-rated) support unattended field deployment; however, long-term barometric stability requires periodic zero-reference updates using known local station pressure data.
How is data security handled during wireless transmission?
Wi-Fi transfers use WPA2-Enterprise authentication and TLS 1.2 encryption; no data is stored on cloud servers—transfers occur exclusively between the device and authenticated local network endpoints.
What is the warranty coverage and service support structure?
Graywolf provides a 2-year limited warranty covering parts and labor; extended service plans include priority calibration turnaround, loaner unit provisioning, and remote diagnostics via secure TeamViewer sessions with certified field engineers.