Series-O-4

Supported Applications

The Dwyer Series O-4 Outside Air Temperature Sensor is designed for monitoring ambient air temperatures in outdoor applications. The product overview identifies suitability for agricultural house ventilation and HVAC and building automation systems.

Operating Conditions & Performance

The series operates within an ambient temperature range of -40 to 250°F. Accuracy varies by sensor type: ±0.22°C @ 25°C (±0.4°F @ 77°F) for Thermistor models and ±0.3°C @ 0°C (±0.54°F @ 32°F) for RTD models. The enclosure is rated NEMA 4X (IP66), verified by a test certificate compliant with IEC/EN 60529:2013.

Configuration Options

The Series O-4 offers multiple sensor element configurations to match specific control system requirements. The housing features integral mounting tabs and includes a removable terminal block for electrical connection. Key configurable attributes include:

• Sensor Types: 10 kΩ type III thermistor, 10 kΩ type II thermistor, 3 kΩ thermistor, Pt100 Ω RTD, Pt1000 Ω RTD, and 20 kΩ thermistor.
• Housing Material: NEMA 4X weatherproof housing.
• Sheath/Wetted Materials: 304 SS probe sheath with a diameter of 0.235" (5.97 mm) and an overall length of 3.5".
• Certifications: Meets the technical requirements of EU Directive 2011/65/EU (RoHS II).

The series supports models O-4A, O-4B, O-4C, O-4D, O-4E, and O-4F. Overall enclosure dimensions are listed as a height of 4" [101.6], width of 3-31/64" [88.5], and depth of 6-3/8" [161.48].

Key Product Differences

Variants within the Series O-4 are distinguished by their internal sensor element type, as defined in the model chart:

• O-4A: 10 kΩ type III thermistor.
• O-4B: 10 kΩ type II thermistor.
• O-4C: 3 kΩ thermistor.
• O-4D: Pt100 Ω RTD.
• O-4E: Pt1000 Ω RTD.
• O-4F: 20 kΩ thermistor.