HJ WH-1 Microenvironment Differential Pressure, Temperature & Humidity Monitor
| Brand | HJ Purification |
|---|---|
| Origin | Shanghai, China |
| Manufacturer Type | Direct Manufacturer |
| Product Category | Domestic |
| Model | WH-1 |
| Instrument Type | Differential Pressure & Thermo-Hygrometer |
| Price | USD 630 (FOB Shanghai) |
| Pressure Range | 0–125 Pa |
| Temp. Range | 5–40 °C |
| RH Range | 10–90 %RH |
| Pressure Accuracy | ±1 Pa |
| Temp. Accuracy | ±0.3 °C (5–40 °C) |
| RH Accuracy | ±2 %RH (10–90 %RH) |
| Power Supply | DC 8.4 V |
| Operating Environment | 5–40 °C / 10–90 %RH |
| Dimensions | 200 × 90 × 30 mm |
Overview
The HJ WH-1 Microenvironment Differential Pressure, Temperature & Humidity Monitor is an engineered field instrument designed for continuous, real-time monitoring of three critical environmental parameters—differential pressure (ΔP), ambient temperature, and relative humidity—in controlled or classified environments. Built upon a dual-sensor architecture, the device integrates a high-stability piezoresistive differential pressure transducer with calibrated NTC thermistor and capacitive humidity sensing elements. Its core measurement principle relies on static pressure comparison across two isolated ports (e.g., cleanroom vs. anteroom, ISO Class 5 vs. ISO Class 7 corridor), enabling precise quantification of airflow direction and containment integrity. Unlike general-purpose thermo-hygrometers, the WH-1 is purpose-built for compliance-driven applications where pressure differentials directly reflect HVAC system performance, barrier integrity, and regulatory adherence—particularly in GMP-compliant pharmaceutical manufacturing, aseptic processing suites, and biosafety level (BSL)-2/3 laboratories.
Key Features
- Simultaneous triple-parameter acquisition: differential pressure (0–125 Pa), temperature (5–40 °C), and relative humidity (10–90 %RH) — all displayed concurrently on a backlit LCD interface.
- High-fidelity differential pressure sensing with ±1 Pa accuracy over full scale, traceable to NIST-traceable calibration standards; suitable for verifying ISO 14644-3 recommended pressure gradients (e.g., ≥10 Pa between adjacent cleanroom zones).
- Integrated dual-port pressure inlet design with quick-connect fittings (¼” barbed) for rapid deployment across inter-zonal ducts, doorways, or HEPA filter housings without external manifolds.
- Ruggedized ABS housing (200 × 90 × 30 mm) with IP54-rated ingress protection, optimized for mobile use in dynamic production floors and static monitoring in QA/QC labs.
- DC 8.4 V lithium-polymer power architecture supporting >12 hours of continuous operation; includes low-battery indicator and auto-sleep mode to extend field service life.
- No internal data logging memory — intentionally designed for direct operator readout and integration into facility-wide Building Management Systems (BMS) via optional analog output modules (0–5 V or 4–20 mA, sold separately).
Sample Compatibility & Compliance
The WH-1 is not a sample-analysis instrument but a fixed-point environmental surveillance tool. It operates exclusively in gaseous media (ambient air, filtered process air, nitrogen-purged enclosures) and is incompatible with corrosive, condensing, or particulate-laden airstreams without upstream filtration (e.g., 0.3 µm particulate pre-filter recommended for HVAC duct applications). The device meets electromagnetic compatibility requirements per IEC 61326-1 (industrial environment), and its sensor calibration protocols align with ISO/IEC 17025–accredited practices. While not certified to UL/CE for permanent installation, it satisfies functional verification criteria outlined in EU GMP Annex 1 (2022), FDA Guidance for Industry: Sterile Drug Products Produced by Aseptic Processing (2004), and ISO 14644-2:2015 clause 8.3 for routine differential pressure monitoring during operational qualification (OQ) and performance qualification (PQ).
Software & Data Management
The WH-1 operates as a standalone, firmware-controlled hardware monitor with no embedded operating system or wireless connectivity. All measurements are presented in real time on the local display; no onboard storage, USB interface, or cloud synchronization is provided. For audit-ready documentation, users must manually record readings or integrate the unit with third-party SCADA/BMS platforms using optional analog signal outputs. When deployed in regulated environments subject to 21 CFR Part 11, raw WH-1 data must be captured and archived through validated external systems that provide electronic signatures, audit trails, and change control — the WH-1 itself does not support user authentication, electronic records, or ALCOA+ principles natively. Calibration certificates include serial-numbered sensor IDs, as-found/as-left data, and uncertainty budgets compliant with ISO/IEC 17025 reporting conventions.
Applications
- Verification of pressure cascades across cleanroom classifications (e.g., ISO 5 → ISO 7 → ISO 8 corridors) per ISO 14644-1 and EU GMP Annex 1 Section 4.22.
- Monitoring of isolation barriers in sterile compounding pharmacies (USP ) and hazardous drug handling isolators (USP ).
- Validation of airlock pressurization sequences during material transfer in biopharmaceutical fill-finish facilities.
- Environmental trending during HVAC commissioning, recommissioning, and seasonal recalibration cycles.
- Supporting root-cause analysis of particle excursions by correlating transient ΔP anomalies with concurrent temperature/humidity shifts.
FAQ
Can the WH-1 measure absolute pressure or only differential pressure?
The WH-1 measures only differential pressure between two connected points. It does not provide absolute or gauge pressure values.
Is the unit supplied with calibration documentation?
Yes — each WH-1 ships with a factory calibration report listing measured deviations at five pressure points (0, 25, 50, 100, 125 Pa), temperature points (10, 20, 30 °C), and humidity points (20, 50, 80 %RH), traceable to national metrology institutes.
What maintenance is required?
Annual recalibration is recommended; sensor drift is typically <0.5 Pa/year under stable operating conditions. No consumables or user-serviceable parts are included.
Does it comply with FDA 21 CFR Part 11?
No — the WH-1 lacks electronic record generation, audit trail, or user access controls. It serves as a manual readout device only; compliance must be achieved at the system level via integrated BMS or validated data acquisition software.
Can it be used outdoors or in unconditioned spaces?
No — its specified operating range (5–40 °C, 10–90 %RH) excludes freezing, condensing, or high-UV environments. Use only within climate-controlled facilities or temporary conditioned enclosures.
