Upgrading a Mark II to a Mark III

Reference, Installation, and Operations Manual

June 2013

3-9000-743 Rev S

 

 

C.4.5 Emission rate, stacked emission rate, and firing sequence

The emission rate is the period between firing two different transducers. The stacked emission rate is the period between consecutive firings of a single transducer when stacking is used (i.e., the stack size is not set to ‘None’).

For the Mark II meter, the default emission rate is 32 ms and the default stacked emission rate is 8 ms. For the Mark III meter, the desired emission rate and stacked emission rate are set via the EmRateDesired and StackEmRateDesired data points, respectively. Setting these data points to zero (their default value) indicates that the meter should use the fastest available emission rates which are typically between 2 and 8 ms.

In order to achieve the fastest possible emission rates, the default transducer firing sequence (selected via FireSeq) should be used.

When converting a Mark II configuration for use in a Mark III, the Daniel MeterLink configuration conversion feature does not modify the Mark III meter’s EmRateDesired, StackEmRateDe- sired, and FireSeq data points (which should be at default values).

C.4.6 Chord failure threshold

The Mark II PctFail parameter specifies the maximum threshold for the percentage of discarded chord firings in a batch before a chord is flagged as failed. The Mark III utilizes a similar threshold but with different perspective: the MinPctGood data point specifies the minimum threshold for the percentage of good chord firings in a batch for a chord to be considered good (i.e., not failed). Thus, MinPctGood is calculated as (100-PctFail).

C.4.7 Flow velocity estimation when a chord is failed

The Mark III uses an improved method for estimating the average weighted flow velocity in the event of a chord failure. The new method is described in detail in Section 6.1.6.

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Emission rate, stacked emission rate, and firing sequence