PUREN PSC-I Automatic Precipitation Sampler

Overview

The PUREN PSC-I Automatic Precipitation Sampler is an engineered field-deployable instrument designed for long-term, unattended collection of wet and dry atmospheric deposition samples in compliance with national and international environmental monitoring protocols—including ISO 9060 (spectral solar irradiance), ASTM D5907 (total suspended particulate analysis), and EPA Method IO-3.1 (wet deposition sampling). It operates on a dual-bucket, four-link mechanical actuation system that enables sequential, contamination-free switching between precipitation and dry deposition modes. The unit integrates a high-sensitivity comb-type precipitation sensor—capable of detecting rainfall intensities as low as 0.05 mm/h or individual raindrops ≥0.5 mm in diameter—alongside a thermostatically controlled heating element to prevent condensation artifacts, melt accumulated snow, and actively evaporate residual moisture post-event prior to lid closure. This ensures sample integrity across diverse climatic conditions, including sub-zero environments (−40 °C) and high-humidity, high-wind (Beaufort Level 9) exposure.

Key Features

• Dual-mode sampling architecture: automatic transition between open precipitation collection and closed dry deposition capture based on real-time meteorological detection.
• Heated sampling head with programmable dew-point compensation and post-precipitation drying cycle to eliminate fog, dew, and residual meltwater interference.
• Robust stainless steel chassis and food-grade polyethylene sampling buckets—chemically inert, UV-stabilized, and compliant with EPA SW-846 Method 5035A for organic leachate preservation.
• Double-sealed bucket mechanism with precision-aligned gasket interface ensures zero cross-contamination during mode switching.
• Low-power standby operation (2 W) and intelligent load management during active sampling (100 W max), optimized for remote grid-connected or solar-hybrid deployments.
• Wide operational envelope: validated performance from −40 °C to +50 °C ambient temperature and up to 100 % relative humidity without condensation ingress.

Sample Compatibility & Compliance

The PSC-I accommodates standard 1-L to 5-L volumetric collection vessels compatible with EPA Methods 1631E (mercury in precipitation), 300.0 (IC analysis of anions), and ISO 6222 (microbiological enumeration). Its 1.2-m sampling height conforms to WMO Guide to Meteorological Instruments and Methods of Observation (CIMO Guide, Chapter 12) for representative bulk deposition assessment. All wet-deposition samples remain stable for ≤24 h at ambient temperature or can be integrated with optional refrigerated storage modules (1–5 °C) meeting GLP-compliant cold-chain requirements. The system’s material composition complies with EU REACH Annex XIV restrictions and carries no SVHCs above reporting thresholds.

Software & Data Management

While the PSC-I operates autonomously without embedded data logging, it serves as the foundational hardware platform for integration with PUREN’s PSC-II and PSC-III series controllers—enabling full traceability under FDA 21 CFR Part 11 and ISO/IEC 17025 audit frameworks. When paired with the optional PC-based PUREN PrecipLog™ software suite (Windows 95+ compatible), users gain access to time-stamped event logs (start/end time, cumulative volume), configurable alarm thresholds, automated PDF report generation, and export to CSV/LabVIEW-compatible formats. Audit trails include operator ID, timestamped configuration changes, and firmware revision history—supporting ISO 14001 environmental management system documentation.

Applications

• Long-term atmospheric chemistry monitoring networks (e.g., CASTNet, EMEP, GAW).
• Acid rain and nutrient deposition studies (SO₄²⁻, NO₃⁻, NH₄⁺, Ca²⁺, Mg²⁺ quantification).
• Heavy metal flux assessment (Pb, Cd, Hg, As) in industrial and rural catchments.
• Radioactive fallout surveillance (e.g., ¹³⁷Cs, ⁹⁰Sr) following nuclear incident response protocols.
• Validation of chemical transport models (CTMs) such as CMAQ and GEOS-Chem through empirical wet scavenging coefficient calibration.
• Urban airshed studies evaluating chloride deposition impacts on infrastructure corrosion rates.

FAQ

Does the PSC-I support remote telemetry or cellular data transmission?
No—the PSC-I is a standalone sampler without built-in communication interfaces. Remote monitoring requires upgrade to the PSC-III series with RS-485/USB or optional GSM/GPRS modules.
Can the unit be calibrated for quantitative rainfall measurement?
It is not a certified rain gauge; however, its comb sensor output correlates linearly with intensity (mm/h) and may be cross-referenced against NIST-traceable tipping-bucket gauges per ASTM D7347 for method validation.
Is the heating element certified for explosion-proof environments?
No—it is rated for general outdoor industrial use (IP65 enclosure) but lacks ATEX/IECEx certification for hazardous locations.
What maintenance intervals are recommended for field deployment?
Biannual inspection of gasket integrity, sensor cleaning with deionized water, and verification of lid actuation timing using simulated precipitation triggers.
Are replacement buckets available with pre-acidified liners for trace-metal analysis?
Yes—PUREN offers optional 1-L HDPE buckets with ultraclean 1 % HNO₃ pre-rinsing and sealed nitrogen-purged packaging, certified to <0.1 ng/L blank levels per EPA Method 1631E.