How your ultrasonic flowmeter works

1
How your ultrasonic flowmeter works!!

• Install the sensors properly
• Input the correct parameters
• Do not input unnecessary parameters
• That is basically ALL!

2
Prepare yourself

• Do you have-
• Ruler, Calculator and Marker?
• Sand paper and a piece of cloth?
• Plastic gauge paper (For Z mounting)?
• Silicone grease?
• Thickness gauge and thermometer (If any)?
• Instruction manual and quick reference?

3
Select the measuring position

• No rusty pipe (cleaner is better)
• Use VERTICAL PIPE if possible
• If horizontal pipe is used, straight pipe length
  to be 10D upstream and 5D downstream
• Pipe to be full of bore
• Avoid welded part

4
Polish the pipe

• Polish the pipe with sand paper to remove the
  painting/coating on the pipe!
• Clean up the surface of pipe with a piece of
  cloth to get better contact!!

5
Measure the pipe outer circumference

• Do not believe paper information for the pipe
  size! (Actual pipe size always different from
  the data)
• Diameter of pipe Circumference/3.142

6
Measure the pipe thickness

• In most cases, the data for pipe thickness is not
  available. Better to have one thickness gauge to
  get better accuracy!

7
Input correct parameters

• Most of errors could be created by wrong pipe
  parameter.
• To input all correct pipe parameters is
• the key for USFM to works!!!

8
Mount the sensors

• Follow page 55 to 59 of Instruction manual
• Dont be stingy with the silicone grease (3mm
  thick at least)!!
• Dont be lazy to measure the mounting dimensions!
  (Use plastic gauge paper and marker)

9
Zero adjustment

• Basically USFM does NOT need zero adjustment
  (Many people misunderstand this point)
• DO NOT use MANUAL ZERO when you cannot stop the
  flow (In fact, most cases do not allow to stop
  the flow)
• Do CLEAR in ZERO ADJUST menu
• Then,
• If you can stop the flow,
• use MANUAL ZERO to get better accuracy!!

10
Calibration

• Do NOT use this function!
• Just confirm the value in CALIBRATION to be
  ZERO 0.000m/S
• SPAN 100.00
• CALIBRATION does not mean real calibration. This
  function means electrical output shift of zero
  and span points. ? Read page 27 of instruction
  manual!

11
Check 3 points

• Signal bar 3 bars or more
• Status display NORMAL
• Waveform As per ? of page 50 of Manual
• 2nd peak to be approx. 0.5V
• (5000 Data/1 Division).
• 3rd peak to be about double
• of 2nd peak.
• The highest peak to be
• Approximately 2V (20,000 Data).

12
If the signal NOT proper

• Tighten the sensor element holder.
• Gain TRANSMISSION VOLTAGE
• X1 X2 X4 X8
• If still NOT yet proper, Check all parameters
  again!
• Relocate the sensors
• Change V to Z method
• If NOT yet proper,
• Change the sensors to 0.5Mhz sensors

13
If FLOW RATE indicates 0.000with normal condition

• Check below parameters
• CALIBRATION SPAN to be 100.00
• CUT OFF to be 0.01m/s or less

If FLOW RATE indicates 0.000
????????
14
If FLOW RATE indicates TOO BIG RATE compared with
actual flow rate

• Check the waveform
• Abnormal waveform
• 2nd peak is similar height as 3rd peak.
• The highest peak is after 5th peak.
• Normal waveform
• 2nd peak is about half of 3rd peak.
• The highest peak is 4th or 5th peak.
• Refer to the separate
• Paper for more details.

Install the sensors properly!!
x
15
Use 0.5MHz Sensors!
Mortar lining

• for below cases
• Mortar lining
• Old pipe
• Signal not strong enough (less than 3 bars) even
  with Z method
• 5th digit of model code means signal frequency
• (00.5MHz, 11MHz, 22MHz)
• FLD50/FLW50 0.5MHz sensor

Old pipe
16
The End