Micronics portaflow 220, Руководство пользователя

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5: Troubleshooting
34
Portaflow 220 User Manual
(Issue 1.0)
12. Select
Exit
and press
ENTER
to return to the
FLOW READING
menu.
13. The flow reading value displayed is not important. The fact that a reading is obtained indicates that the
instrument is functioning. This value may fluctuate but this is normal.
14. The signal strength indicator at the left of the display should show 3–4 bars.
5.5 Microprocessor Reset Facility
In the rare event that the Portaflow 220 instrument appears to totally hang-up, or displays total gibberish, you
can reset its microprocessor by carefully inserting a straightened paperclip into the pinhole located in the
right-hand side of the instrument to operate the internal reset switch. Hold the paperclip perpendicular to the
instrument while doing this.
5.6 Diagnostics Display
This feature is designed for advanced users and is intended to provide information that will aid the user to
diagnose problems – e.g. no signal strength.
When operating in the
FLOW READING
mode you can access a diagnostics screen by pressing the
Options
function key and then selecting
Diagnostics
from the
FLOW READING OPTIONS
screen. This will display
the operating values for the following parameters.
Calculated time (µs)
This is a value the instrument predicts will be the time in µsecs that it should take for the acoustic wave to
propagate across a particular pipe size. This value is ascertained from the data entered by the user. i.e. Pipe
size, material, sensor set etc.
Actual time (µs)
This is the value the instrument measures as the time taken for the acoustic wave to propagate across the
pipe. It is used to see if the signal is being taken from the burst, at the correct time to get the strongest signal.
This value is normally a few µs below the calculated µs value. If, however, this value is much greater than the
calculated time then there is a problem with the set-up.
Flow (m/s)
This displays flow velocity in m/sec to 3 decimal places.
Signal strength
This is the averaged value of Signal and should be a value between 800 and 1600 – where 800 is
approximately 50%, and 1600 is approximately 100%.
UP/DN time difference
The difference in transit times between the upstream and downstream signals due to the fluid flow.
Propagation µs
Not currently in use.
Signal propagation
Not currently in use.
Fluid propagation rate
This is the sound speed of the fluid calculated using the data entered by the user.
Fluid propagation rate
Calculated from the input data concerning the fluid type and temperature.
Sensor separation
The same value as displayed in the setup screen.