• Flow sensor 380 BTU

Flow sensor 380 BTU

Flow sensor with BTU transmitter


  • Low cost Btu system
  • For cold or hot applications
  • BACnet and ModBus® protocols
  • Scaled pulse output
Water, Pharmaceutical media
max. flow:
from 6.3 up to 595 l/min
from -20 up to 125 °C
max. pressure:
from 0 up to 27 bar
Water & waste water industry, Chemical industry, HVAC


General information

The series 380 Btu systems provide a low cost system for metering cold or hot systems. The 380CS/HS can accurately measure flow and temperature differential to compute energy. Utilizing either BACnet or Modbus RS 485 communications protocols or a scaled pulse output, the Btu meter can interface with many existing control systems.

The rugged design incorporates an impeller flow sensor and two temperature probes. One temperature probe is conveniently mounted directly in the flow sensor tee. The second temperature probe is placed on either the supply or the return line depending on ease of installation for the application. These minimal connections help simplify installation and save time.

Commissioning of this meter can be completed in the field via a computer connection or setup at the factory with the customers requirements. Setup includes energy measurement units, measurement method, communication protocol, pulse output control, fluid density and specific heat parameters. 


Measuring principle

Heat meters

Heat meters

The heat meters use the highly precise ultrasonic transit time measuring principle, for which two ultrasonic sensors are externally mounted on the pipeline and connected to the electronic. The ultrasonic sensors work alternately as transmitter and receiver, and mutually send ultrasonic signals. During these transmissions, the respective signal transit times of the to-and-from signals (t1, t2) are measured.  

The electronic measures the difference of the transit time of the ultrasonic signals going with and against the flow direction t1 and t2. These signals are either decelerated or accelerated by the medium flow. The difference produced in both signal transit times is proportional to the flow rate and is used together with the pipeline geometry for a precise flow calculation