Reference, Installation, and Operations Manual

Section 6: Meter operation

3-9000-743 Rev S

June 2013

 

 

 

Data updates

When the Option Board is used, the Daniel Mark III Ultrasonic Gas Flow Meter samples the input analog signal(s) and updates the corresponding data point(s)

(LiveFlowPressure, LiveFlowTemperature) once per second regardless of the input selection (disabled, live, or fixed).

Every five seconds, the meter updates the “in-use” flow-condition pressure and temperature values (FlowPressure, AbsFlowPressure, FlowTemperature) depending upon the input selection, validity of the input data, and the selected data source upon alarm according to Table 6-6.

Table 6-6 Flow-condition pressure and temperature data source
Input TypeData ValidityData Source Upon Alarm“In-Use” Data Source

(EnablePressureInput or

(PressureValidity or

(FlowPressure or

(FlowPOrTSrcUponAlarm)

EnableTemperatureInput)

TemperatureValidity)

FlowTemperature)

 

 

 

 

 

Disabled

N/A

N/A

“In-Use” value unchanged

 

 

 

 

Live

Valid

N/A

Average of live values

 

 

 

(LiveFlowPressure or Live-

 

 

 

FlowTemperature)

 

 

 

 

 

Invalid*

Last good value

“In-Use” value unchanged

 

 

 

 

 

 

Fixed

Fixed data point

 

 

 

(SpecFlowPressure or Spec-

 

 

 

FlowTemperature)

 

 

 

 

Fixed

Valid

N/A

Fixed data point

 

 

 

(SpecFlowPressure or Spec-

 

 

 

FlowTemperature)

 

 

 

 

 

Invalid

Last good value

“In-Use” value unchanged

 

 

 

 

 

 

Fixed

Fixed data point

 

 

 

(SpecFlowPressure or Spec-

 

 

 

FlowTemperature)

 

 

 

 

*Live input can be invalid due to (a) one or more live values is/are at or outside the alarm limits, or (b) the input is being cali- brated.

Flow-condition pressure and temperature

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