Principle of Measurement :

The transit time flow meter utilizes two transducers that function as both ultrasonic transmitters and receivers. The transducers are clamped on the outside of a closed pipe at a specific distance from each other.  The transducers can be mounted in V-method where the sound transverses the pipe twice, or W-method where the sound transverses the pipe four times, or in Z-method where the transducers are mounted on opposite sides of the pipe and the sound crosses the pipe once.  This selection of the mounting method depends on pipe and liquid characteristics.  The flow meter operates by alternately transmitting and receiving a frequency modulated burst of sound energy between the two transducers and measuring the transit time that it takes for sound to travel between the two transducers.  The difference in the transit time measured is directly and exactly related to the velocity of the liquid in the pipe

Typical Applications : 

Our Portable Utrasonic Flow meter can be virtually applied to a wide range of measurements. A variety of liquid applications can be accommodated: ultra-pure liquids, potable water, chemicals, raw sewage, reclaimed water, cooling water, river water, plant effluent, etc.  Because the instrument and transducers are non-contacting and have no moving parts, the flow meter can not be affected by system pressure, fouling or wear. Standard transducers are rated to 90 ºC. Higher temperatures can be accommodated. For further information, please consult XINSIER TECHNOLOGY for assistance.

Main technical Specifications :

Linearity	0.5%
Repeatability	0.2%
Accuracy	±1% of reading at rates>0.2 mps
Response Time	0-999 seconds, user-configurable
Velocity	±32 m/s
Pipe Size	15mm-6000mm
Totalizer	7-digit totals for net, positive and negative flow respectively
Liquid Types	Virtually all liquids
Security	Setup values Modification Lockout. Access code needs unlocking
Display	4×8 Chinese characters or 4×16 English letters
Communication Interface	RS-232, baud-rate: from 75 to 57600. Protocol made by the manufacturer and compatible with that of the FUJI ultrasonic flow meter. User protocols can be made on enquiry.
Transducer Cord Length	Standard 5m x 2, optional 10m x 2
Power Supply	3 AAA built-in Ni-H batteries. When fully recharged it will last over 12 hours of operation. 100V-240VAC for the charger
Data Logger	Built-in data logger can store over 2000 lines of data
Manual Totalizer	7-digit press-key-to-go totalizer for calibration
Housing Material	ABS
Case Size	210x90x30mm
Handset Weight	500g with batteries

Transducers Mounting Allocation : 

The first step in the installation process is the selection of an optimum location in order to obtain a more accurate measurement. For this to be completed effectively, a basic knowledge about the piping and its plumbing system would be advisable.An optimum location would be defined as a straight pipe length full of liquid that is to be measured. The piping can be in vertical or horizontal position.

Examples of optimum locations.

Principles to selection of an optimum location

• Install the transducers on a longer length of the straight pipe. The longer the better, and make sure that the pipe is completely full of liquid.
• Make sure that the temperature on the location does not exceed the range for the transducers. Generally speaking, the closer to the room temperature, the better.
• Take the pipe fouling into consideration. Select a straight lengthof a relatively newer pipe. If the condition is not satisfying, consider the fouling thickness as part of the liner for a better result.

Some pipes have a kind of plastic liner, and between the outer pipe and the liner there may be a certain thickness difference that will prevent the ultrasonic waves from direct traveling. Such conditions will make the measurement very difficult. Whenever possible, try to avoid this kind of pipes. If impossible, try our plug-in transducers that are installed permanently on the pipe by drilling holes on the pipe while liquid is running inside.