Series-RHPX

Supported Applications

The Dwyer Series RHPX Humidity and Temperature Transmitter monitors humidity and temperature for building control functions. The series is designed to support applications in building energy management systems, commercial HVAC systems, clean rooms, museums, and data centers.

In addition to relative humidity and temperature measurements, the transmitter can be configured to supply absolute or relative humidity, dew point, and enthalpy calculations.

Operating Conditions & Performance

The Series RHPX utilizes capacitive polymer sensors for humidity measurement across a range of 0 % to 100 % humidity. Temperature is measured from -40 °C to 60 °C (-40 °F to 140 °F). Humidity sensor accuracy is model specific, rated at ±2 % or ±3 %, at 10 % - 90 % RH and 25 °C (77 °F).

Temperature sensor performance varies by element type:

• Solid State Band Gap: ±0.9°F @ 77°F (±0.5°C @ 25°C)
• Thermistor: ±0.2°C @ 25°C (±0.36°F @ 77°F) for analog models only
• RTD: DIN Class B; ±0.3°C @ 0°C (±0.54°F @ 32°F) for analog models only

The operating temperature range is -40°C to 60°C (-40°F to 140°F); with LCD: -20°C to 60°C (-4°F to 140°F). Storage temperatures are rated from -40°C to 70°C (-40°F to 158°F), or -30°C to 70°C (-22°F to 158°F) with LCD. The enclosure material is UL 94 V-0 and carries an IP66 rating.

Configuration Options

The series offers extensive configuration options for enclosures, sensor configurations, outputs, and passive temperature inputs.

Enclosure & Sensor Configurations

Housing styles include small (S) or large (L) enclosures. RH sensor configurations support:

• Bronze sintered filter (B)
• Duct mount with plenum plastic probe and hydrophobic filter (D) or rapid response filter (E)
• Duct mount with SSTL probe and radiation filter (F) or rapid response filter (G)
• HDPE filter with cover (S), without cover (W), or factory installed solar radiation shield (H)
• Remote humidity sensor (-R models only, available with 1.2 m to 4.9 m cable lengths)

Outputs & Communication

Analog output models provide field-selectable signals of 4-20 mA or 0-5 V dc, 0-10 V dc at 5 mA max for both humidity and active temperature. Communicating models support BACnet MS/TP protocol or Modbus® RTU with supported BAUD rates from 9600 to 115200.

Passive Temperature Sensors

Analog models can accept passive temperature inputs including:

• Solid state band gap (Types II and III)
• Thermistor: Curves A, B, and F
• Platinum RTD DIN 385 or Balco 1K: Curves D and E

Additional Options & Accessories

An optional two-line alphanumeric display (LCD) is available. The series supports NIST traceable calibration certificates, a six-plate solar radiation shield (RHRS), duct mount adapter plates (A-RHPX-PLATE), and depth adjustment brackets (A-RHPX-DEPTH).

Key Product Differences

The Series RHPX is distinguished by accuracy class (-2 for 2 % RH, -3 for 3 % RH) and enclosure size. Analog models support passive temperature sensor inputs which are not available on communicating models. Remote sensor configurations (-R) require specific cable length options (04, 08, 12, or 16). UL 2043 compliance is limited to specific wall mount and duct mount model combinations as defined in the ordering guide.