RH650-Series

Supported Applications

The Omega RH650 is a handheld multi-functional thermo-hygrometer and moisture meter designed for water damage restoration contractors, HVAC/R system installers and technicians, facility maintenance professionals, and electronics manufacturers. The device measures ambient temperature, relative humidity (RH), absolute humidity, GPP (mixing ratio), dew point, atmospheric pressure, vapor pressure, and moisture levels in various materials.

Documented media compatibility includes non-corrosive gases and vapors, dry or moist air, wood, wallboard, masonry, hardwood, softwood, soil, paper, and powders. The instrument supports both internal (pinless) relative moisture measurement and external absolute moisture measurement using a pin-type probe.

Operating Conditions & Performance

The RH650 operates within an ambient temperature range of -40 to 60 °C (-40 to 140 °F). Storage temperatures are specified from -40 to 70 °C (-40 to 158 °F).

Measurement ranges and accuracies for the series include:

• Ambient Temperature: -40 to 199.9 °C (-40 to 392 °F) with ±0.5 °C (±0.9 °F) accuracy
• Relative Humidity: 0 to 100% RH with ±3% RH accuracy
• Absolute Humidity: 0 to 100 g/m³ with ±3 g/m³ accuracy
• GPP (Mixing Ratio): 0 to 100 g/kg with ±3 g/kg accuracy
• Dew Point: -40 to 100 °C (-40 to 212 °F) with ±0.5 °C (±0.9 °F) accuracy
• Atmospheric Pressure: 200 to 1100 hPa with ±2 hPa accuracy
• Vapor Pressure: 0 to 100 hPa with ±1 hPa accuracy
• Moisture Level (Pinless): 0 to 100% (non-invasive, up to 3/4 in. penetration) with ±3% typical accuracy
• Moisture Level (Pin-Type): 0 to 100% WME (Wood Moisture Equivalent) with ±3% WME accuracy

The device features a backlit LCD providing a 3-digit primary readout and a 4-digit secondary readout. Typical response time for humidity and temperature is less than 30 seconds.

Configuration Options

The RH650 series includes the following configurable functions and accessories:

• Data Management: Stores and recalls up to 20 pairs of readings; features Min/Max, Data Hold, and a 30-minute Auto Power Off function.
• Alarms: Settable high and low alarms for RH, relative moisture level, and absolute moisture level.
• Sensor Modes: Zero reset capability in pinless moisture level mode; switchable between internal (pinless) sensor and external probe via a standard 3.5mm audio jack connector.
• Housing & Power: Constructed of gray and yellow plastic, powered by an included 9V battery.

The package includes the RH650 unit, pin-type moisture probe (with a 3/8 in. insertion length), sensor protection cap, soft pouch, user's manual, and 9V battery.

Key Product Differences

The series is represented by the single model variant RH650. The device distinguishes between two moisture measurement methods: a non-invasive pinless sensor for relative levels in materials up to 3/4 in. penetration, and an invasive pin-type probe with steel pins for absolute Wood Moisture Equivalent (WME) readings.

Users must observe safety warnings regarding the sharpness of the external probe's steel pins and avoid operating the device in the presence of flammable or explosive gases.