Q: How to judge if the instrument works properly?
A: Generally speaking, when ‘R’ is displayed in the lowest right corner
of the LCD display, the instrument is working properly. Otherwise,
please check section 3.1 of the User Manual for error code
interpretations.
Q: How to judge if the transducers are installed properly?
A: Go to window M90. Check the following three most important data:
- the
transit-time ratio, which is shown at the upper right corner, should
be between 97% and 103%.
- the two
signal strength data (one for each transducer), which are shown on the
lower left side (S = xxx, xxx), should be between 600 and 999 for
each.
- the
signal quality Q, which is shown on the lower right side (Q = xx),
should be between 60 and 99.
If the
above three criteria are met, you can be sure that your transducer
installation are good.
Please
refer to section 2.9 of the User Manual for details.
Q: How do I know if my measurement results are good?
A: Similar to the above question. Go to window M90 and make sure the
three criteria are met.
Q: Can I
switch to window M90 quickly to check signal quality and working
status?
A: When the current window is a displaying window (one between M00 to
M09), pressing ENT key will lead to window M90. Press ENT key again to return to the previous window.
Window M90
displays very useful diagnostic information, such as signal intensity,
signal quality and transit-time ratio. It is frequently used by user
for transducer installation and system debugging.
Q: How to judge the flow direction in the pipe?
A: There are two transducer connectors on the handset, one is marked as
RED, another is marked as BLUE. The transducer cable should be
connected to the corresponding connectors correctly.
Make sure that the instrument works properly.
Then, check the flow rate display. If the value is POSITIVE, the direction of the flow will be
from the RED transducer to the BLUE transducer; if the value is
NEGATIVE, the direction will be from the BLUE transducer to the RED
transducer.
Q: How to stabilize the flow rate reading?
A: Use the software damper. Go to window M40 to set up the damper. If the value is ‘0’,
your damper is not used. Enter a number between 1 and 10 to see if you
get a more stable reading.
A bigger number brings a more stable effect. But bigger damper numbers will slow down
the measurement response speed.
Q: How to use the zero-cutoff function?
A: The number displayed in window M41 is called the zero-cutoff value. When the
absolute value of the measured flow rate is less than the zero-cutoff
value, the measured flow rate will be replaced with ‘0’. This is to
avoid any invalid accumulation when the actual flow is below the
zero-cutoff value.
The zero-cutoff operation does not affect the flow measurement when the actual flow is greater than the zero-cutoff value.
Q: How to set up a zero point?
A: When the flow in a pipe is absolutely stopped, the flow meter could still give a small non-zero flow rate reading. In order to make the measurement accurate, it is necessary to remove this “zero point” reading.
Window M42 allows us to take care of this issue. At first, the user should make sure that the
liquid in the pipe is totally stopped (no velocity). Then, go to
window M42 and press the ENT key to start the zero point setup function.
We recommend
the user to conduct this zero procedure after installing the
transducers on a pipe if the condition is allowed.
Q: How to use the
built-in data logger?
A: The built-in data logger has a space of 24K bytes of memory, which
will hold about 2000 lines of data. Shenitech has developed a PC
Software, StufManager software, to facilitate the configuration and
data management of the data logger. Click here to download the brochure.
If you do not use StufManager software, you are still able to
configure the data logger manually:
- Use M50 to turn on the logger and to select the items that are going
to be logged.
- Use M51 to set up the logging starting time, logging time interval
and the time each logging lasts.
- Use M52 to select the data storage direction. Select To Buffer
- Use M53 to view the data in the logger buffer.
- To clear the logger buffer, go to window M52, select Clear Buffer
option and press ENT key.
- To turn off the logger, go to window M50 and select Off.
If you do not use StufManager software, you may also download the
logger data into your PC through RS232 link and Windows Hyper Terminal
Utility.
Q: How to calibrate the
flowmeter?
A: After installing the transducers on a pipe, we recommend the user to
do in-situ calibration if high-accuracy is crucial or whenever the
condition is allowed.
The simplest but accurate way to calibrate the flowmeter is to use
weighting method. You just need a liquid container, a watch and a
scale. You can easily derive the average volumetric flow rate by this
method.
On the other hand, you may use the flowmeter's manual totalizer
(window M38) to totalize the volumetric flow of the same period of
time, which also gives you an average flow rate. The ratio of the two
flow rates will be the Scale Factor of this flowmeter.
You may need to change the flow rate and do the calibration one more
time to get better estimation on the Scale Factor. When you are
confident on the result, enter the Scale Factor to window M45.
Your flowmeter has been calibrated. Please click here to get the detailed
description of the calibration procedure. |