SKC Chek-mate 375 Series Gas Flow Calibrator
| Brand | SKC |
|---|---|
| Origin | USA |
| Model | Chek-mate 375 Series |
| Flow Ranges | 5.0–30.0 L/min (High), 0.50–5.0 L/min (Medium), 20–500 mL/min (Low) |
| Accuracy | ±1% of reading within specified ranges, ±2.5% outside |
| Operating Temperature | 0–40 °C |
| Pressure Range | 700–1090 mbar |
| Altitude Limit | up to 3050 m |
| Power | 9 V alkaline battery (≈30 h operation, auto-shutdown after 15 min idle) |
| Weight | ~232–236 g |
Overview
The SKC Chek-mate 375 Series Gas Flow Calibrator is a portable, differential-pressure-based primary standard instrument engineered for field and laboratory verification of air sampling pump performance across occupational hygiene, environmental monitoring, and industrial hygiene applications. Unlike inferential flow meters, the Chek-mate 375 employs a precision laminar flow element coupled with integrated temperature and barometric pressure sensors to compute true volumetric flow under actual sampling conditions—enabling real-time compensation per ISO 8503-2 and ASTM D3195 conventions. Its design adheres to the physical principles of Hagen–Poiseuille flow, ensuring high reproducibility without moving parts or mechanical wear. The device serves as a traceable reference standard for validating personal and area air sampling systems compliant with OSHA, NIOSH, ISO 13137, and EU Directive 2017/164 recommendations.
Key Features
- Dual-compensated measurement: Simultaneous real-time correction for ambient temperature (0–40 °C) and atmospheric pressure (700–1090 mbar), critical for accurate volumetric flow reporting at variable altitudes up to 3050 m.
- Three dedicated flow-range models: Optimized sensor configurations for high-flow (375-50300: 5.0–30.0 L/min), medium-flow (375-0550: 0.50–5.0 L/min), and low-flow (375-00205: 20–500 mL/min) applications—each calibrated independently per ISO/IEC 17025 requirements.
- NIST-traceable certification: Supplied with an individual calibration certificate issued by an ISO/IEC 17025-accredited laboratory, documenting uncertainty budgets, reference standards used, and environmental conditions during calibration.
- CalChek™ digital interface (High & Medium models): Enables bidirectional communication with SKC CalChek-compatible sampling pumps—including automated pump speed adjustment, pass/fail status logging, and timestamped calibration event records.
- Robust field architecture: IP40-rated enclosure; no moving parts; operable in any orientation; internal particulate filter protects sensing elements from dust ingress during routine use.
- Human-centered operation: One-button activation; backlit LCD with rolling 30-second moving average display; low-battery indicator; auto-power-off (15 min idle timeout) extending 9 V alkaline battery life to ≈30 hours.
Sample Compatibility & Compliance
The Chek-mate 375 Series is validated for use with all common air sampling media—including PVC, PTFE, and glass fiber filters; sorbent tubes (e.g., charcoal, silica gel, XAD); and bioaerosol cassettes—when deployed with SKC, Thermo Fisher, Casella, and other major-brand sampling pumps. It meets the accuracy criteria stipulated in NIOSH Manual of Analytical Methods (NMAM) Chapters 1000, 1020, and 2500 series; OSHA Method ID-121; and ISO 13137:2013 (Workplace atmospheres — Performance requirements for pumps used for personal sampling). All units bear CE marking per Directive 2014/30/EU (EMC) and 2014/35/EU (LVD), confirming conformity with essential health and safety requirements for electrical equipment.
Software & Data Management
While the Chek-mate 375 operates as a standalone hardware calibrator without embedded firmware-upgrade capability, its CalChek™-enabled variants generate structured calibration logs compatible with SKC’s CalChek Manager desktop software (Windows-based). These logs include pump ID, date/time stamp, target vs. measured flow, environmental parameters, operator ID (if entered), and pass/fail status—supporting audit-ready documentation aligned with GLP and GMP frameworks. Raw analog output is not provided; however, the device supports manual transcription into LIMS or electronic lab notebooks (ELN) via standardized CSV templates. Calibration certificates satisfy FDA 21 CFR Part 11 requirements for electronic record retention when stored in controlled, versioned repositories.
Applications
- Pre- and post-sampling verification of personal air sampling pumps in occupational exposure assessments (e.g., respirable crystalline silica, metal fumes, organic vapors).
- Field validation of low-flow passive samplers and diffusion badges where volumetric accuracy directly impacts quantitative exposure reconstruction.
- Quality assurance audits in contract laboratories performing ISO 17025-accredited air analysis.
- Training and competency assessment for industrial hygienists and safety professionals conducting NIOSH-approved sampling protocols.
- Verification of flow stability during extended-duration sampling campaigns (>8 hours) under fluctuating ambient conditions.
FAQ
What calibration standards does the Chek-mate 375 comply with?
It is calibrated per ISO/IEC 17025 by an accredited third-party laboratory using NIST-traceable primary standards; certificates document measurement uncertainty, environmental conditions, and traceability chain.
Can the Chek-mate 375 be used above 3050 m altitude?
No—its pressure compensation algorithm is validated only up to 3050 m (10,000 ft); operation beyond this limit may exceed stated accuracy specifications.
Does it require periodic recalibration?
Yes—SKC recommends annual recalibration or prior to critical sampling campaigns; users should verify calibration status before each deployment using the built-in zero-check function.
Is the CalChek™ interface compatible with non-SKC pumps?
Only with pumps explicitly certified for CalChek™ communication; compatibility is limited to SKC’s own CalChek-enabled pump models (e.g., AirChek TOUCH, AccuVac Elite).
How is temperature and pressure compensation implemented?
Via onboard thermistor and piezoresistive barometer; compensation follows the ideal gas law and laminar flow correction factors defined in ISO 8503-2 Annex B.
