Siemens FUS1010 User Manual download pdf (Page 70)

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1010NFM-3JSection 2

How to Use the MTYmatic Command

You can repeat MTYmatic (performed during the Initial Makeup) to correct an inaccurate Actual MTY

setting if conditions do not allow you to repeat the Actual Empty procedure.

NOTE: Only use the MTYmatic procedure when the pipe is full.

To start MTYmatic:

To access the [Empty Pipe Set] option list press

Move the cursor next to [MTYmatic] press

To invoke MTYmatic press

ENT

How to Use the Set Empty Command

Use [Set Empty] to enter a number that represents the signal strength level consistent with an empty

pipe. [Set Empty] uses non-linear scaling. There is no direct correlation between the number you enter

and any standard amplitude unit. If you set the number too low, the meter may not detect a true empty

pipe. If you set it too high, it could trigger the empty pipe alarm, suspending flow measurement, even

though the liquid is flowing.

To enter an Empty Pipe Alarm Threshold:

To access the [Empty Pipe Set] option list press

To move the cursor to [Set Empty] press

Press . The current empty threshold number appears in a pop-up window.

Use the numeric keys to type a new Set Empty number.

To store the Set Empty number press

2.4.10 ZERO FLOW ADJUST MENU

Unlike turbine meters ultrasonic transit-time meters provide active flow measurement right down to

zero flow, however, the measurement of the transit-time delta is dependent on the similarity or “match”

of the electronics, cables and ultrasonic transducers. Consequently some flow offset (or zero offset)

may be present in any installation. To eliminate this residual zero offset Controlotron has developed

several different methods to insure proper zero flow compensation. The following paragraphs de-

scribe each method and when they should be used.

AutoZero

When the 1011 transducers are mounted in the Reflect Mode configuration (see paragraph 3.1.5) the

AutoZero routine is automatically invoked at the end of the Initial Makeup. Flow does not have to be

stopped to perform AutoZero since only the pipe wall signal is used in determining the zero offset and

not the liquid component. The AutoZero routine performs a one-time analysis of the pipe wall compo-

nent of the ultrasound signal to quantify any residual mismatch in the hardware. Once the AutoZero

routine is complete, the system memorizes this measured zero offset and subtracts this value from

the flow reading.

ENT

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Siemens FUS1010 User Manual Page 70