Vaisala WXT534 Weather Transmitter

Overview

The Vaisala WXT534 Weather Transmitter is a compact, high-reliability environmental sensing module engineered for continuous, unattended monitoring of ambient temperature, relative humidity, and atmospheric pressure. As a dedicated variant within the modular WXT530 series, the WXT534 omits wind and precipitation sensing hardware while retaining the same robust PTU (Pressure-Temperature-Humidity) measurement core and digital architecture. It operates on Vaisala’s proprietary capacitive thin-film polymer sensor technology for humidity and silicon piezoresistive sensing for barometric pressure—both integrated into a field-replaceable, sealed PTU module. This design eliminates calibration drift due to mechanical wear or contamination and supports long-term stability without routine recalibration. The device complies with IEC 60945 maritime environmental requirements and is rated IP65 (IP66 with mounting adapter), ensuring operational integrity in exposed outdoor deployments including coastal, alpine, and industrial perimeters.

Key Features

• Integrated PTU sensor module with factory-calibrated capacitive humidity and piezoresistive pressure elements
• Modular architecture compatible with WXT530-series accessories, including analog input expansion for third-party sensors (e.g., solar radiation, external thermistors)
• Low-power operation: typical current draw of 3 mA at 12 VDC under standard 1-minute measurement intervals; supports solar-powered installations via ultra-low standby consumption (0.1 mA)
• Multiple digital output interfaces: SDI-12 v1.3, RS-232, RS-485, and RS-422—enabling seamless integration into SCADA systems, dataloggers (e.g., Campbell Scientific CR series), and IoT edge gateways
• Configurable measurement frequency (1/s, 1/min, 1/hr) and communication protocols including ASCII polling, NMEA 0183 v3.0 sentences, and SDI-12 command sets
• Optional heater circuit (12–24 VDC / 12–17 VAC) for dew-point suppression and ice mitigation in sub-zero or high-humidity environments
• Compact form factor (Ø140 × 200 mm) and lightweight construction (<1.2 kg) facilitate rapid deployment on masts, rooftops, or mobile platforms

Sample Compatibility & Compliance

The WXT534 is designed for direct exposure to ambient air without protective aspiration or radiation shielding—making it suitable for general-purpose meteorological profiling, HVAC system monitoring, agricultural microclimate networks, and environmental compliance reporting. Its measurement ranges meet ISO 7726 (Ergonomics of the thermal environment) and WMO No. 8 (Guide to Meteorological Instruments and Methods of Observation) recommendations for Class II station-grade parameters. While not certified to GLP or FDA 21 CFR Part 11 out-of-the-box, its deterministic ASCII/NMEA output format, timestamped data packets, and configurable logging intervals support traceable data acquisition when deployed with compliant dataloggers. The device conforms to EMC Directive 2014/30/EU and RoHS 2011/65/EU, and its enclosure meets UL 61010-1 safety standards for industrial measurement equipment.

Software & Data Management

Vaisala provides the free-to-use WXT Manager desktop application for configuration, firmware updates, and diagnostic logging via USB-to-serial or direct RS-232 connection. All communication is ASCII-based and human-readable, eliminating proprietary binary dependencies. Raw sensor outputs are delivered as structured strings (e.g., “!0R000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000……” — truncated for illustration). For enterprise deployments, Vaisala’s optional Insight Cloud platform supports secure MQTT ingestion, automated QA/QC flagging (e.g., RH saturation checks), and audit-trail generation compatible with ISO/IEC 17025 documentation workflows.

Applications

• Automated weather stations (AWS) in remote or low-infrastructure locations where power autonomy is critical
• Environmental monitoring networks for regulatory reporting under EU Directive 2008/50/EC (ambient air quality)
• Building energy management systems (BEMS) requiring real-time psychrometric inputs for HVAC optimization
• Research-grade microclimate studies in agroecology, forestry, and glaciology
• Industrial process ambient condition logging for ISO 9001:2015 clause 7.1.5 (monitoring and measuring resources)
• Mobile environmental sensing on unmanned aerial vehicles (UAVs), autonomous ground vehicles, and marine buoys

FAQ

Is the WXT534 suitable for use in freezing conditions?
Yes. The device operates continuously from −52 °C to +60 °C and includes an optional heater circuit to prevent condensation or frost accumulation on the sensor housing.
Can the WXT534 be calibrated in-field?
No—calibration is performed at the factory using NIST-traceable standards. The PTU module is designed as a sealed, replaceable unit; end users do not perform sensor-level adjustments.
Does the WXT534 support Modbus RTU or TCP?
No. It natively supports SDI-12, RS-232/485/422 with ASCII and NMEA 0183 protocols only. Modbus integration requires an external protocol converter.
What is the expected service life of the PTU module?
Vaisala specifies a minimum operational lifetime of 5 years under continuous outdoor exposure, with typical field deployments exceeding 7–10 years when installed per manufacturer guidelines.
Is firmware update capability available over-the-air (OTA)?
Firmware updates require physical serial connection via USB-to-RS232 adapter and the WXT Manager application; OTA is not supported.