ARA FTS Flow Calibration System

Overview

The ARA FTS Flow Calibration System is a precision-engineered, portable instrument designed for field and laboratory verification of volumetric air flow rates in environmental and occupational hygiene sampling systems. It operates on the well-established Venturi tube principle—leveraging differential pressure measurement across a precisely machined, ISO 5167-compliant Venturi element to determine mass-conserved volumetric flow under real-time ambient conditions. Unlike thermal mass flow meters, the FTS provides true volumetric calibration traceable to NIST standards without requiring gas-specific calibration factors, making it universally applicable across sampling media including particulate (PM_2.5, PM₁₀), VOC, and aerosol collection protocols. The system simultaneously measures and logs three critical environmental parameters—actual volumetric flow rate, ambient temperature, and barometric pressure—enabling automatic conversion to standardized reference conditions (e.g., 25°C and 760 mmHg per EPA Method IO-3 or 20°C and 760 mmHg per ISO 10780). Its robust architecture supports both push-mode (upstream pressurization) and pull-mode (downstream vacuum) configurations, ensuring compatibility with low-flow personal samplers, high-volume stack monitors, and fixed-site ambient air monitoring stations.

Key Features

• Venturi-based primary flow standard with NIST-traceable calibration certificates supplied with each interchangeable element
• Three user-swappable Venturi modules covering discrete, non-overlapping ranges: 1–3 LPM (low-flow personal sampling), 2–9 LPM (medium-flow area monitoring), and 9–25 LPM (high-flow industrial hygiene applications)
• Integrated, factory-calibrated platinum RTD temperature sensor (±0.5°C accuracy) and piezoresistive barometer (±5 mmHg over 250–800 mmHg range)
• Rugged, IP65-rated weather-resistant enclosure constructed from impact-resistant polycarbonate and aluminum alloy, rated for continuous operation from −30°C to +50°C
• Intuitive, menu-driven LCD interface with dedicated soft keys for rapid setup, zeroing, and data review—no external PC required for basic calibration tasks
• Bluetooth 5.0 wireless module enabling secure, encrypted pairing with iOS and Android mobile devices via the ARA FieldLink™ companion app for remote logging, report generation, and firmware updates
• Rechargeable NiMH battery pack delivering up to 60 hours of continuous operation; includes wall-mount charging cradle with status LED indicators
• User-definable standard temperature and pressure (STP) settings compliant with regional regulatory frameworks—including US EPA, EU EN 12341, and ISO 10780—ensuring audit-ready documentation

Sample Compatibility & Compliance

The FTS Flow Calibration System is validated for use with all major classes of air sampling instrumentation, including but not limited to: SKC AirChek® and Gilian GilAir® personal pumps; Thermo Scientific™ pDR series aerosol monitors; TSI SidePak™ and DustTrak™ real-time dust meters; and custom-built low-flow passive diffusion samplers. Its measurement methodology satisfies key regulatory requirements for flow verification under US EPA Methods IO-2 (for PM₁₀ samplers), IO-3 (for PM_2.5 samplers), and Compendium Method TO-15 (for canister-based VOC sampling). All factory calibrations are performed in accordance with ISO/IEC 17025-accredited procedures and include full uncertainty budgets per GUM (Guide to the Expression of Uncertainty in Measurement). The device supports GLP-compliant audit trails when used with the optional ARA DataVault™ software suite, which maintains electronic records meeting FDA 21 CFR Part 11 requirements for signature, timestamp, and change control.

Software & Data Management

Data acquisition and reporting are managed through two interoperable platforms: the embedded firmware interface for immediate field verification and the ARA FieldLink™ mobile application for advanced analytics. FieldLink™ enables real-time visualization of flow stability, temperature drift, and pressure compensation residuals; exports CSV- and PDF-formatted calibration reports with embedded metadata (operator ID, location GPS coordinates, instrument serial number, and calibration due date); and supports offline mode for remote site deployments. For enterprise-level integration, the optional ARA DataVault™ desktop software provides centralized database management, automated compliance alerts (e.g., overdue calibrations), multi-user role permissions, and export to LIMS environments via HL7 or ASTM E1384 interfaces. All stored datasets retain full traceability to original raw sensor readings—including differential pressure delta-P values, thermistor resistance curves, and absolute pressure transducer outputs—for forensic reprocessing if required during regulatory audits.

Applications

• Pre- and post-sampling calibration verification of personal and area air sampling pumps in OSHA and NIOSH-compliant industrial hygiene programs
• Field validation of low-flow (<5 LPM) PM_2.5/PM₁₀ ambient monitoring networks operating under US EPA SLAMS or FRM/FEM protocols
• QA/QC auditing of continuous emission monitoring systems (CEMS) extractive sampling lines prior to stack testing campaigns
• Calibration of passive badge-type samplers (e.g., OSHA #56 for formaldehyde) using gravimetric flow verification techniques
• Verification of flow-dependent analytical instrument inlets—including GC-MS, FTIR, and DOAS systems—where precise volumetric delivery is critical to detection limit integrity
• Training and proficiency testing for environmental technicians conducting method-defined flow checks per ISO 17025 internal audit requirements

FAQ

Is the FTS Flow Calibration System suitable for use in explosive or hazardous atmospheres?
No. The FTS is not intrinsically safe or ATEX-certified. It must be operated only in non-classified locations per NEC Article 500 guidelines.

Can I perform calibrations at altitudes above 3,000 meters?
Yes. The integrated barometer automatically compensates for local atmospheric pressure; however, users must verify that the selected Venturi element remains within its specified Reynolds number operating envelope at reduced density conditions.

Does the Bluetooth interface support connection to multiple devices simultaneously?
No. The FTS maintains a single active Bluetooth SPP (Serial Port Profile) session. Concurrent connections require sequential pairing via the FieldLink™ app.

How often does the unit require recalibration?
ARA recommends annual NIST-traceable recalibration, or after any physical impact exceeding 50 g-force, as documented in the instrument’s internal event log.

Are replacement Venturi elements available with individual calibration certificates?
Yes. Each Venturi module ships with a unique, serialized NIST-traceable certificate listing its K-factor, discharge coefficient, and uncertainty budget at three flow points across its range.