Shaw SADP-D Portable Dew Point Meter
| Brand | Shaw |
|---|---|
| Origin | United Kingdom |
| Model | SADP-D |
| Type | Portable Dew Point Meter |
| Measurement Principle | Aluminum Oxide Capacitive Sensor |
| Dew Point Range | –110 °C to +20 °C (configurable sub-ranges) |
| Accuracy | ±2 °C DP (traceable to NPL/NIST) |
| Repeatability | ±0.2 °C DP |
| Operating Temperature | –10 °C to +60 °C |
| Storage Temperature | –40 °C to +80 °C |
| Max Operating Pressure | 30 kPa(g) |
| Sample Flow Rate | 2–10 L/min (recommended: 2–5 L/min) |
| Response Time (dry → wet) | <20 s (–110 °C → –20 °C) |
| Response Time (wet → dry) | <120 s (–10 °C → –60 °C) |
| Display | 126 × 64 pixel backlit LCD |
| Power | Rechargeable Li-ion battery (250 h continuous operation, 6 h recharge) |
| Output Options | RS485 serial, USB, 4–20 mA analog (optional) |
| Calibration | User-accessible 2-point auto-calibration |
| Pressure Dew Point Calculation | Built-in, supports multiple pressure units |
| Data Logging | Real-time storage (optional) |
| Gas Path | Dual stainless-steel inlet/outlet ports (6 mm Swagelok + PTFE tubing) |
| Maintenance | Field-replaceable sensor and molecular sieve cartridge |
Overview
The Shaw SADP-D Portable Dew Point Meter is an industrial-grade, handheld analyzer engineered for high-accuracy, on-site measurement of dew point temperature in compressed air, natural gas, instrument air, and other process gases. It employs a robust aluminum oxide capacitive sensor — a mature, field-proven technology offering long-term stability and resistance to contamination in demanding environments. Unlike semiconductor-based sensors (which are unsuitable for low-dew-point applications due to drift and condensation sensitivity), the SADP-D’s aluminum oxide sensor operates reliably across an exceptionally wide range from –110 °C to +20 °C DP, with selectable sub-ranges optimized for specific applications (e.g., SR: –110 to –20 °C; BL: –80 to +20 °C). The instrument calculates pressure dew point (PDP) in real time using user-input gauge pressure, enabling direct compliance assessment against ISO 8573-1 purity classes or ASTM D1193 specifications for instrument air quality. Its design adheres to fundamental metrological principles: traceability to UK’s National Physical Laboratory (NPL) and US NIST standards is maintained through factory calibration certificates, and full temperature compensation is applied across the entire operating range (–10 °C to +60 °C ambient).
Key Features
- True handheld form factor: Compact, ruggedized housing with IP65-rated enclosure for field durability.
- Multi-unit display: Simultaneous or toggle-view support for °C, °F, ppmv, ppmw, ppbv, g/m³, and lbs/MMSCF — essential for cross-industry reporting (e.g., pharmaceutical compressed air per ISO 8573-1 Class 2 vs. LNG moisture specs in ppmv).
- Integrated molecular sieve drying system: Enables rapid equilibration and stable readings even after exposure to saturated gas streams; eliminates need for external dryers during spot checks.
- Intuitive 5-key interface and 126×64 backlit LCD: Optimized for gloved operation and low-light conditions; menu-driven 2-point field calibration requires no tools or software.
- Extended battery life: 250 hours of continuous operation on a single Li-ion charge — validated per IEC 62133 — minimizing downtime during extended plant surveys.
- Configurable analog and digital outputs: Optional 4–20 mA loop output for integration into DCS/SCADA systems; RS485/USB interfaces support automated data capture and audit-ready logging (GLP-compliant timestamping available with optional software).
Sample Compatibility & Compliance
The SADP-D is validated for use with non-corrosive, non-condensing gas streams including compressed air, nitrogen, argon, natural gas (upstream/distribution), and CO₂. It is incompatible with aggressive halogenated compounds, high-concentration H₂S (>10 ppm), or aerosol-laden streams without upstream filtration (ISO 8573-2 Class 2 particulate filter recommended). Its performance meets key international standards: accuracy and traceability satisfy ISO/IEC 17025 requirements for field instrumentation; pressure dew point calculation aligns with ISO 8573-1 Annex B methodologies; and operational parameters conform to ATEX Category 3G (II 3 G Ex nA IIC T4 Ga) certification when used with approved accessories. For regulated industries, the device supports 21 CFR Part 11-compliant data export when paired with Shaw’s certified PC software — enabling electronic signatures, audit trails, and secure user access control via multi-level password protection.
Software & Data Management
Optional Shaw DewPoint Manager™ software provides full instrument configuration, firmware updates, and raw data export in CSV or XML formats. The application enforces ALCOA+ data integrity principles: each recorded dew point value includes embedded metadata (timestamp, ambient temperature, sample pressure, sensor ID, operator login). Automated report generation supports ISO 8573-1 class verification templates and custom PDF/PPT exports for QA documentation. All stored measurements retain cryptographic hash verification to prevent post-acquisition tampering — critical for FDA- or EMA-audited facilities. Data synchronization is performed over USB or RS485; no cloud dependency ensures compliance with internal IT security policies.
Applications
- Compressed air system validation per ISO 8573-1 (Class 0–4) in pharmaceutical manufacturing and food processing plants.
- Moisture monitoring in natural gas dehydration units and pipeline custody transfer points (meeting GPA 2172 and AGA Report No. 8 requirements).
- Pre-commissioning verification of dryness in power transformer oil-gas systems (IEC 60422).
- Quality control of inert purge gases in semiconductor fab tool chambers.
- Field diagnostics of desiccant dryer performance and regeneration cycle efficiency.
- Environmental chamber humidity profiling where frost point correlates directly with dew point under sub-zero conditions.
FAQ
Is the SADP-D sensor interchangeable in the field?
Yes — the aluminum oxide sensor and integrated molecular sieve cartridge are user-replaceable without tools or recalibration services. Replacement kits include NIST-traceable calibration verification stickers.
Does the instrument compensate for ambient temperature fluctuations during measurement?
Yes — all internal electronics and sensor signal conditioning incorporate real-time ambient temperature compensation across the full –10 °C to +60 °C operating range, ensuring consistent accuracy regardless of environmental conditions.
Can the SADP-D measure dew point under positive pressure without external regulators?
Yes — it accepts sample pressures up to 30 kPa(g) directly. For higher-pressure lines (e.g., 7 bar(g)), a calibrated pressure-reducing regulator must be installed upstream to avoid sensor damage and ensure accurate PDP calculation.
What maintenance intervals are recommended for routine operation?
Annual verification against a chilled-mirror reference standard is recommended. Sensor replacement is typically required every 5–10 years depending on gas composition and exposure history — documented in the built-in service log.
Is the 4–20 mA output linear with respect to dew point temperature or ppmv?
The analog output is configurable: users may select linear scaling to either dew point temperature (°C) or volumetric moisture concentration (ppmv) via the instrument menu, facilitating seamless integration with legacy PLC systems.
