RHE 42

Ex c Field Mount

With its advanced digital signal processing capability and in conjunction with our sensors, the RHE 42 can achieve an ultimate mass flow measurement uncertainty of 0.05 %, making it ideal for both filling and bottling or any kind of high accuracy/reliability plant flow or density measurement. Connectivity includes a full suite of communications buses including Foundation Fieldbus and Modbus TCP/IP. The RHE 42 is a well specified transmitter relevant for large scale plant and project opportunities.


  • Measures Mass Flow, Volumetric Flow, Density and Temperature
  • Outputs 2 x Analog, 2 x Frequency/Pulse, 2 x Digital Status
  • Inputs 2 x Digital
  • PC USB / RHECom, RS 485 / Modbus RTU, Modbus TCP, Foundation Fieldbus and Profibus PA
  • Optional Backlit Color LCD
  • Installation in Hazardous Area
  • Rheonik Assurance Factor®



General Specifications

Enclosure Material

Powder coated aluminum

Enclosure Rating

IP65/Type 4, optional IP66-67/Type 6

Ambient Temperature

-20 to +60°C  / -4 to +140°F, optional -40°C to +65°C / -40°F to 149°F

Integral version depends upon fluid temperature, refer to next page


Enclosure approx. 144 x 108 x 139 mm / 5.67 x 4.25 x 5.47 in

Weight approx. 2.3 kg / 5.1 lbs

User Interface and Configuration

Local Display Version

High contrast backlit LCD color display and 3 x through-glass operator buttons.  Configure locally or with RHECom software

Reduced display visibility below -10°C  / 14°F

Blind Transmitter Version

No local controls. Configure through RHECom software package

Connection to Sensor

Integral/Compact to sensor or remote mount with 3m/10m cable

Cable Entries

2 x ½” NPT for power and I/O

Computer Connection

Via Modbus RTU to PC


6 x resettable forward, reverse and net totalizers for mass and volume

2 x non-resettable totalizers for mass and volume

Analog Outputs

Up to 2 x 4-20mA outputs, active or passive.

Intrinsically safe versions available

Pulse/Freq/Status Outputs

Up to 2 configurable pulse/frequency/status outputs (IEC60946).  Max. 10kHz.  Intrinsically safe versions available (open collector)

Digital Inputs

Up to 2 configurable control inputs (IEC60946).

Intrinsically safe versions available

Digital Data Communications

HART, Modbus RTU, Ethernet (Modbus TCP/IPv4), Foundation Fieldbus H1 (FISCO), Profibus PA

Power Supply

12-24 VDC +/- 10%, 2W typical, 4W maximum

Hazardous Area Approvals