EWSA Air Temperature Sensor for Indoor or Outdoor Use

Supported Applications

The Omega EWSA Series consists of rugged, weatherproof temperature sensors and transmitters designed for wall or pipe mounting in harsh indoor or outdoor environments. The series features a sheathed RTD probe housed within an outer protection tube to support installation where exposure to environmental conditions is expected.

Operating Conditions & Performance

The EWSA Series operates across distinct ambient temperature ranges depending on the configuration and humidity conditions:

• Sensor-only models: -50 to 100°C
• Transmitter models (EWSA-Pt100-TX): -40 to 85°C at 10 to 90% RH non-condensing

The enclosure is rated IP65. The sensor element for the standard model is a Pt100 class A 4-wire RTD, with Pt1000 available on request.

Configuration Options

The series offers configurable options across sensor types and output signals to address specific measurement needs:

• Sensor Types: Standard configuration includes a 6 mm diameter sheathed RTD probe with a stem length of 75 mm, housed in a 12.7 mm outer protection tube.
• Output Signals: Sensor-only variants provide electrical connection via a 4-way screw terminal block for the sensor element. Transmitter models (e.g., EWSA-Pt100-TX) offer a standard scaling of 4 mA at -25°C and 20 mA at 75°C.
• Power Supply: Loop-powered transmitter models operate on 10 to 30 Vdc. Load resistance is calculated as [(V supply - 10)/20] KΩ, e.g., 700Ω @ 24V.

Housing and mechanical features include:

• Enclosure Material: Aluminum alloy box with overall dimensions of 80 W x 75 H x 58 mm D.
• Cable Entry: M20 cable gland fitted for cables ranging from 2.5 to 6.5 mm in diameter.

Key Product Differences

The EWSA Series is differentiated by the presence of an integrated transmitter and sensor element type:

• EWSA-Pt100 (Sensor Only): Features a Pt100 class A 4-wire standard RTD with a screw terminal block connection. Operates in ambient temperatures from -50 to 100°C.
• EWSA-PT100-TX (Transmitter Model): Integrates the sensor with a loop-powered transmitter outputting 4–20 mA scaled for -25°C to 75°C. This configuration utilizes a 2-wire electrical connection and operates in ambient temperatures from -40 to 85°C at 10 to 90% RH non-condensing.
• EWSA-PT1000: A variant utilizing the Pt1000 sensor element, available on request.