Showing posts with label non-invasive flow measurement. Show all posts
Showing posts with label non-invasive flow measurement. Show all posts

Saturday, November 11, 2017

Clamp-on, Transit-time Difference Ultrasonic Flowmeters Ideal for HVAC Retrofit and New Construction

Transit-time Difference Ultrasonic Flowmeters
Transit-time Difference Ultrasonic Flowmeters (Flexim)
There are many reasons for large commercial buildings, medical centers, museums, airports, sports complexes, federal institutions and military complexes to invest in building energy optimization efforts. Better and more efficient operation of HVAC equipment can reduce the buildings energy and operational costs significantly.

Controlling flow, temperature and pumps can provide energy cost savings of over 20%. Many campus energy managers believe that the biggest user of energy in any complex is the HVAC system, and the key to saving energy in HVAC systems is an accurate and reliable flow metering capability.

Better efficiency of the heating and cooling infrastructure of a building also leads to more environmentally friendly buildings, something that has become a social prerogative of building owners and operators.  Older buildings were not built with BTU meters as metering requirements were added to buildings through increased regulations.

Submetering the buildings heating and cooling systems have become increasingly more important, as building owners are both mandated to meter these utilities and have a financial interest in the accuracy of these BTU measurements. The problem historically is that nearly all flow meters are designed for gradual failure due to direct contact with the fluids they are monitoring and the particulate accumulation on the sensors.

Clamp-on, transit-time difference ultrasonic flowmeters are the ideal retro-fit flowmeter, and also should receive strong consideration for new building construction. Transit-time difference ultrasonic clamp on flowmeters exploit the fact that the transmission speed of an ultrasonic signal depends on the flow velocity of the carrier medium - kind of like a swimmer swimming against the current. The signal moves slower against the flow than with it.

How Transit-time Difference Ultrasonic Flowmeters Work

The flowmeter sends ultrasonic pulses through the process medium - one in the same direction as the
flow and one in the opposite direction. The flowmeter's transducers alternate as emitters and receivers. The transit time of the signal going with the flow is shorter than the one going against. The flowmeter measures transit-time difference and determines the average flow velocity of the process medium. Since ultrasonic signals propagate in solids, the flowmeter can be conveniently mounted directly on the pipe and measure flow non-invasively.

Contact Flow-Tech with your questions about any flow measurement application. Reach them at 410-666-3200, or visit

Tuesday, February 28, 2017

Non-invasive, Ultrasonic Flowmeters Are Clear Winners in Wastewater Pumping Stations

non-invasive flowmeters on wastewater pumping stations
Non-invasive flowmeters installed on
wastewater pumping line.
Pumping stations are an integral part of each wastewater network. Flow measurement at such stations is critical as the quantities which are fed to the treatment plant have to be monitored.

Conventionally, magnetic inductive flowmeters are used for such measurement tasks. However, due the medium, which is heavily charged with solid matter, these instruments are subject to wear, leading to incorrect readings and subsequent failure.

Non-invasive ultrasonic flow meters prove to be the better measuring solution. Since these meters measure from outside the pipe wall, there is no wear and tear on the meter making them virtually maintenance-free. Furthermore, there is no need to open the pipe for installation, which would result in at least a partial interruption of operation. There isn't a need for multiple workers or heavy equipment for installation. The entire measuring system, consisting of ultrasonic transducers and a measuring transmitter, is easily carried to the measuring location and installed by a single person. There is no disconnection of pipes or flanged joints, unlike when installing a magmeter. Finally, there is no need for block valves to hold back flow during installation, repair, or replacement.

  • Reliable and accurate non-invasive wastewater flow measurement without any wear and tear or measurement drift
  • Extremely easy to set up a measuring point without any impairment of the plant’s normal operation
  • ATEX-certified transducers with protection degree IP68 for use in hazardous areas as well as in flooded chambers
For more information on non-invasive ultrasonic flow measurement, contact Flow-Tech in Maryland at 410-666-3200, in Virginia at 804-752-3450, or online at