RH318-Series

Supported Applications

The Omega RH318 Series is a handheld hygro-thermometer data logger designed to measure relative humidity, temperature, and dew point. The device features interchangeable digital probes for field measurements and includes a PC interface with Windows software for data processing.

• Relative Humidity measurement
• Ambient Temperature monitoring
• Dew Point calculation

Operating Conditions & Performance

The RH318 Series operates within an ambient temperature range of 0 to 40°C (32 to 104°F) and a relative humidity range of 10 to 90%RH. Storage conditions are specified as -10 to 60°C (14 to 140°F) at 10 to 75%RH.

Performance specifications vary by probe model:

• Probe RP-32: Temperature range of -20 to 60°C (-4 to 140°F) with an accuracy of ±0.8°C (±1.5°F). Humidity accuracy is <10%RH, >90%RH: ±4.0%RH; 10%RH to 90%RH: ±2.0%RH.
• Probe RP-31: Temperature range of -15 to 35°C (-60 to 95°F) with an accuracy of ±0.8°C (±1.5°F); for temperatures <15°C (60°F), >35°C (95°F), refer to the provided figure in the manual. Humidity accuracy is <10%RH, >90%RH: ±5.0%RH; 10%RH to 90%RH: ±3.0%RH.

The device offers a resolution of 0.1%RH, 0.1°C, and 0.1°F. Response time is documented as Humidity: 180 sec. (at 190; in slowly moving air); Temperature: 10 sec. Sensor hysteresis is <1.5%RH.

Configuration Options

Sensor Technology & Data Logging

• Sensors: Electronic capacitance polymer film sensor for humidity; NTC thermistor for temperature.
• Data Capacity: 16,000-record data logger with a sample rate of 2 times per second.
• Display: Dual display showing relative humidity and temperature simultaneously.

Housing & Power

The meter dimensions are 185mm(L) × 65mm(W) × 36mm(H), with a weight of approximately 285g. The probe measures 15mm Diameter x 94mm(L). Standard accessories include an instruction manual, 9V Battery (alkaline), Windows software, carrying case, and USB cable.

• Power Supply: 9V Battery (alkaline) with a lifetime of approximately 80 hours. An optional AC adapter is available (9 VDC; 8-10VDC Max).

Certifications

The series carries CE marking and ISO 9001 Certification (Stamford, CT and Manchester, UK).

Key Product Differences

The RH318 Series is offered with interchangeable digital probes. The primary variation lies in the sensor performance envelope depending on whether Probe RP-31 or Probe RP-32 is utilized.

• Probe RP-32: Supports a wider temperature range (-20 to 60°C) and tighter humidity accuracy (±2.0%RH within 10–90%RH).
• Probe RP-31: Operates in a narrower temperature band (-15 to 35°C for ±0.8°C accuracy) with slightly reduced humidity accuracy (±3.0%RH within 10–90%RH). Accuracy outside the -15 to 35°C range requires reference to specific documentation figures.

Both probes share identical resolution and response time characteristics as defined in the series specifications.