Graywolf AS-202A Hot-Wire Anemometer & Air Flow Meter

Overview

The Graywolf AS-202A is a handheld, microprocessor-controlled hot-wire anemometer engineered for high-fidelity air velocity and volumetric flow rate measurement in HVAC commissioning, cleanroom qualification, laboratory safety validation, and indoor air quality (IAQ) assessments. Based on constant-temperature anemometry (CTA), the instrument maintains a heated platinum-tungsten sensor wire at a fixed temperature differential above ambient; convective cooling by airflow induces measurable resistance changes proportional to local air velocity. This principle delivers fast response times (<0.5 s), low turbulence sensitivity, and stable performance across transient and laminar flow conditions—critical for accurate duct traverse, fume hood face velocity mapping, and supply/exhaust balancing. Unlike cup or vane anemometers, the AS-202A’s thermal sensing architecture enables reliable measurements at low velocities (down to 0.1 m/s) and in confined geometries where mechanical probes cannot rotate freely.

Key Features

• Articulated 90° bent-tip probe (AS-202A) optimized for access into grilles, diffusers, duct corners, and fume hood sashes without repositioning the main unit.
• Dual-mode operation: direct velocity readout (m/s) and calculated volumetric flow (m³/h or CFM) when paired with user-defined cross-sectional area inputs.
• Wolf OS embedded operating system with real-time clock, multi-language UI (English, Spanish, German, Chinese), and non-volatile memory retaining >10,000 timestamped data points.
• Modular software architecture supporting optional certified calculation modules: DuctCal (for ISO 14644-3 compliant duct traverse averaging), HoodCal (ASHRAE 110-compliant fume hood face velocity analysis), and VentCal (EN 13725-based outdoor air intake quantification).
• Integrated annotation capability: embed voice memos, text notes, and geotagged photos directly into measurement records during field acquisition.
• USB-C and Bluetooth 5.0 connectivity for synchronized data transfer to Windows/macOS workstations and cloud-based QA/QC platforms.

Sample Compatibility & Compliance

The AS-202A is validated for use in non-corrosive, non-explosive ambient air streams within –10 °C to +50 °C and ≤95% RH (non-condensing). Its hot-wire probe is not rated for particulate-laden or high-humidity saturated airstreams without periodic calibration verification. The instrument meets electromagnetic compatibility (EMC) requirements per IEC 61326-1 and carries CE marking for professional environmental monitoring applications. All firmware and software modules comply with FDA 21 CFR Part 11 electronic record/electronic signature (ER/ES) requirements when used with audit-trail-enabled configurations. Calibration certificates traceable to NIST standards are provided with each unit and may be renewed annually per ISO/IEC 17025-accredited procedures.

Software & Data Management

Graywolf Professional Suite operates natively on the AS-202A’s Wolf OS and supports offline data review, statistical summary generation (mean, min/max, standard deviation), and customizable report templates compliant with GLP and GMP documentation standards. Raw data exports include ASCII-delimited (.csv), structured XML (.xml), and print-ready PDF formats—with embedded metadata (operator ID, location tag, probe serial number, calibration due date). The suite enforces role-based access control and maintains immutable audit trails for all data modifications, deletions, or report finalizations—fully satisfying regulatory expectations for laboratory and facility validation documentation.

Applications

• HVAC system commissioning and TAB (Testing, Adjusting, Balancing) per SMACNA and NEBB protocols.
• Cleanroom classification (ISO 14644-1/3) and routine monitoring of unidirectional airflow uniformity.
• Fume hood performance verification per ANSI Z9.5 and ASHRAE 110—face velocity profiling, tracer gas containment testing support.
• Building envelope leakage assessment via blower door auxiliary velocity mapping.
• Occupational hygiene surveys requiring localized air movement characterization near process equipment or exhaust points.

FAQ

Is the AS-202A suitable for measuring airflow in high-temperature ducts?

No. The probe and electronics are rated for ambient air up to +50 °C. For elevated-temperature applications (>60 °C), contact Graywolf for thermally insulated probe variants or pitot-static alternatives.
Does the instrument require annual recalibration?

Yes. While factory-calibrated against NIST-traceable standards, ISO/IEC 17025 recommends annual verification under field-use conditions. Graywolf offers accredited recalibration services with full uncertainty budgets.
Can DuctCal be used with round and rectangular ducts interchangeably?

Yes. DuctCal supports both geometries and automatically applies ISO 14644-3 traverse point selection logic—including log-Tchebychev and equal-area methods—based on user-specified duct dimensions and aspect ratio.
Is Wolf OS upgradeable in the field?

Yes. Firmware updates are delivered via encrypted .fwu files through USB or Bluetooth and preserve all stored data and user configurations during installation.
What is the battery life under continuous logging mode?

Up to 12 hours with alkaline AA batteries (4×) or 18 hours with rechargeable NiMH cells, verified at 25 °C and 1 Hz sampling rate. Low-power sleep mode extends standby time to 30 days.