1. Sensor Power Consumption


  • Voltage required: 24V DC
  • Voltage range acceptable: 18-36V DC
  • Current required (min): 120 mA
  • Power required (maximum): 3W
  • Recommended DC supply power rating: at least 5W
  • Fuse (if required) rating: >500 mA Slow-blow fuse


For multiple sensors, multiply by the number of sensors to be powered to properly specify the power supply.


Rheonics sensors can be configured over USB but the sensor will NOT make any measurements over USB supplied power. For operation (factory floor or in lab), it is recommended to power the sensor using a galvanically separated, certified power supply from a reliable source. Check power supply to ensure you get the required voltage and current without significant noise.


2. Power Supply Specification

When selecting a power supply to power the Rheonics sensors, select one with the following ratings:

  • Voltage output: 24V DC
  • Power rating: 5W or higher
  • Current rating: 200 mA or higher


Often power supply are available that meet the local regulatory approvals and can take all of the following inputs: DC, AC, Single-phase, 2-phase, 3-Phase.

3. Maximum input voltage allowed on Power Supplies for Ex sensor configurations


Power supplies for EX sensors should comply with the following characteristics:

•Voltage output: 24V DC

•Power rating: 5W or higher

•Current rating: 200 mA or higher

•Input:  240V Maximum AC Single Phase, this is exclusive for Ex sensor configuration and would be the best to protect the zener barriers used in the configuration, only single phase power supplies should be used.


4. Glossary


DC : Direct Current

V : Volt

W : Watts

SMET : Rheonics sensor electronics

GND : Ground


5. Installation
  • Connect a 24V DC supply to the power input terminals on the sensor electronics (SME/SMET).
  • Power input terminals on sensor electronics (SME/SMET) are labeled with 24 V DC + and – GND.


It is important to avoid ground loops in the setup / plant where the SMET is used. Ground loops can lead to excessive currents on the ground / return wire of the SMETs 24V power supply which can damage the unit.


To prevent this, we strongly recommend that the SMET is powered by a separate 24V power supply with galvanic separation. Otherwise, the SMET might be permanently damaged.


It is also fine to power the sensor from the 24V DC outputs available on PLC and IPC.

6. Examples and Clarifications

We show below some examples of industrial power supplies that can be used with the sensor.


This is by no means an endorsement of any specific brand. Any adequately rated power supply from reputable manufacturers will give you stable, noise free and safe power supply for your sensor operation. 


It is customer's responsibility to ensure that the power supply that is sourced meets the local and national requirements for their installation. 


We do not sell power supply due to the varying global connector and power ratings. However, the power supplies mentioned below are quite universally available or have suitable similar alternatives.


A fuse is not necessary from the DC converter but if you plan to use one then a 200 mA 24V fuse is sufficient. The device has a maximum power input requirement of under 5W.  


7. Industrial Power Supply
  • Used in enclosures/cabinets
  • Used for powering sensor in the plant (Industrial power supplies provide a higher level of reliability in connection compared to power adapter connected to power strip)
  • Single, 2- or 3-phase power supply can be used which has a DC output of 24V DC


These typically tend to be DIN rail mount units as shown below:


Figure above shows various types of DIN rail mounted power supply from a supplier (SIEMENS). These are typically mounted on DIN rails as shown below:


Other types used inside equipment are Switching Power Supply (SPS):




Laboratory Power Supply

  • Used for benchtop tests
  • Used in Labs


These typically tend to be power adapters connected directly to the wall outlet or benchtop power supplies.


Power Adapters (Wall mount style)

These can be directly mounted on the wall outlet. They will need an adapter to connect from the plug on the adapter to the SMET. Alternatively the jack can be removed and the wire ends can be directly used (recommended to use a crimped connection on the ends).

The photo above shows 24V DC power adapters with European plug. Similar types are available with US, Australian, UK, Japanese, and other plugs.


When searching your local supplier for these adapters, the English keywords are "24V DC power adapter".


Benchtop Power Supply

These are versatile and often have selection of power outputs. It is important that the power output is set to 24V DC. A lower voltage may not be sufficient for the sensor to operate and a higher voltage can damage the SMET electronics.


Photo above shows a typical benchtop power supply from supplier (Rohde & Schwarz), there are a lot of other suppliers of these benchtop power supply. Often these are programmable with ability to select the voltage and current.


Below we provide a few links to order pages for power supplies as an example, these are only used here as examples and the customer should select one that is easily available and they trust.


Wall adapter with global plug options: https://www.digikey.com/en/products/detail/mean-well-usa-inc/GE12I24-P1J/7703284


DIN rail mount power supply: https://mall.industry.siemens.com/mall/en/WW/Catalog/Product/6EP3331-6SB00-0AY0

[ Siemens LOGO!POWER 24 V / 1.3 A Stabilized power supply input: 100-240 V AC output: DC 24 V / 1.3 A ]


Benchtop power supply: https://www.keysight.com/us/en/products/dc-power-supplies/bench-power-supplies/e3640-series-bench-power-supply-30-100w.html