AirMar WX Series Replacement Humidity Sensor Model 33-627-02

Overview

The AirMar WX Series Replacement Humidity Sensor (Model 33-627-02) is a field-serviceable, OEM-grade capacitive relative humidity (RH) transducer engineered for integration into Airmar’s marine and environmental weather monitoring platforms. Designed specifically for the WX-series intelligent weather stations—including the 110WX, 120WX, 150WX, 200WX, and 220WX—it operates on the principle of polymer-based capacitive sensing, where changes in ambient humidity alter the dielectric constant of a hygroscopic polymer layer, resulting in a proportional shift in capacitance. This analog signal is conditioned and scaled to deliver a stable, linear output compatible with the host station’s internal data acquisition architecture. The sensor does not incorporate active temperature compensation; instead, it relies on the host unit’s integrated temperature measurement and firmware-based RH correction algorithms per ISO 7726 and IEC 60751 standards. Its compact form factor and standardized mechanical interface enable true hot-swap replacement without recalibration or firmware reconfiguration.

Key Features

• True plug-and-play replacement—no tools, soldering, or calibration required
• Capacitive sensing element with polymer dielectric for long-term stability and low hysteresis (<2% RH)
• Designed to meet marine-grade environmental resilience requirements, including resistance to salt-laden air and cyclic thermal stress
• Compatible with Airmar’s NMEA 2000® and NMEA 0183 data protocols via the host WX station’s communication stack
• Factory-trimmed at 25°C and 50% RH under controlled metrology conditions traceable to NIST standards
• Low-power operation (typical current draw <1 mA at 12 VDC), minimizing impact on station battery life

Sample Compatibility & Compliance

This sensor is exclusively validated for use within the Airmar WX-series ecosystem and is not intended for standalone deployment or integration into third-party systems without prior validation. When installed, it maintains full functional interoperability with the host station’s internal barometric pressure, wind, and temperature modules—enabling consolidated environmental parameter reporting (e.g., dew point, heat index, wet-bulb temperature). Installation modifies the overall enclosure integrity: the ingress protection rating of the weather station degrades from its original IPX6 or higher to IPX4 (splash-resistant only), as defined in IEC 60529. Users operating in high-humidity, heavy-rain, or deck-wash environments must assess this reduced sealing performance against operational risk profiles. The sensor itself carries no CE, UKCA, or FCC markings, as it is classified as a component—not a standalone end-product—under EU RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006.

Software & Data Management

The 33-627-02 functions transparently within Airmar’s proprietary WX firmware environment. Humidity data is embedded in standard NMEA 2000 PGNs (e.g., 130310 – Environmental Parameters) and NMEA 0183 sentences (e.g., MWV, MWD, or proprietary $WIXDR extensions), enabling seamless ingestion by chartplotters, VMS systems, and cloud-based maritime telemetry platforms such as Furuno TZtouch, Raymarine Axiom, or Maretron DSM series. No additional driver installation or configuration utility is required. All humidity readings are subject to the host station’s built-in data logging interval (configurable from 1 s to 60 s), with timestamped values stored in non-volatile memory for post-deployment retrieval. While the sensor itself does not support audit trails or digital signatures, the host WX units compliant with firmware v3.2+ provide GLP-aligned metadata tagging (including sensor ID, install date, and last self-test timestamp) for regulatory traceability in commercial fishing or coastal monitoring applications.

Applications

• Real-time marine meteorological monitoring on commercial vessels, research ships, and autonomous surface vehicles (ASVs)
• Coastal and offshore buoy networks requiring cost-effective RH redundancy and field-replaceable subsystems
• Environmental compliance logging for port authority air quality reporting (e.g., correlating RH with particulate matter dispersion modeling)
• Integration into educational marine science instrumentation labs where modular sensor replacement supports hands-on curriculum on environmental transduction principles
• Supplemental humidity input for dynamic vessel stability calculations where moisture-induced air density variation affects aerodynamic loading models

FAQ

Can this sensor be used outside the Airmar WX-series weather stations?
No. It is mechanically and electrically optimized for the WX-series mounting interface and signal conditioning circuitry. Standalone use will result in undefined output and potential damage.
Does installing this sensor void the weather station’s warranty?
Installation by authorized personnel using Airmar-recommended procedures does not void warranty coverage. However, improper installation causing physical damage to the housing or PCB may invalidate limited warranty terms.
Is periodic recalibration required?
Airmar specifies no user-performed recalibration. Field verification against a traceable reference hygrometer (e.g., Rotronic HC2-S) is recommended annually in critical applications, per ISO 5725-2 guidelines for intermediate precision checks.
What is the expected service life under typical marine conditions?
Based on accelerated life testing per MIL-STD-810G Method 507.6, the sensor exhibits median operational longevity of 5 years when exposed to continuous salt fog (5% NaCl, 35°C) and UV radiation equivalent to 30°N latitude exposure.