Technical data

Flow-condition pressure and temperature data sourceTable 4-8:
Input Type (Enable-
PressureInput or En-
ableTemperatureIn-
put)
Data Validity ( Pressur-
eValidity or Tempera-
tureValidity )
Data Source Upon
Alarm ( FlowPOrTSr-
cUponAlarm )
“In‑Use” Data Source
( FlowPressure or
FlowTemperature )
Disabled N/A N/A “In‑Use” value un-
changed
Live Valid N/A Average of live values
( LiveFlowPressure or
LiveFlowTempera-
ture )
Invalid* Last good value “In‑Use” value un-
changed
Fixed Fixed data point (Spec-
FlowPressure or Spec-
FlowTemperature)
Fixed Valid N/A Fixed data point (Spec-
FlowPressure or Spec-
FlowTemperature)
Invalid Last good value “In‑Use” value un-
changed
Fixed Fixed data point (Spec-
FlowPressure or Spec-
FlowTemperature)
Note
*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 calibrated.
The flow-condition absolute flow pressure is calculated as shown below.
Flow-condition absolute flow pressure Equation 4-4:
ρ
a
bs, f
= ρ
f
+ ρ
Atmosphere
I
nputPressureUnit = False
(
Gage
)
ρ
a
bs, f
= ρ
f
InputPr
essureUnit = True
(
Absolute
)
P
abs, f
flow-condition absolute pressure (MPaa) (AbsFlowPressure)
P
f
flow-condition pressure (MPa if InputPressureUnit=FALSE, MPaa if
InputPressureUnit=TRUE) (FlowPressure)
P
Atmosphere
(specified) atmospheric pressure (MPaa) (AtmosphericPress)
Daniel Liquid Ultrasonic Flow Meters calibration and configuration parameters
56 Daniel 3810 Series Operations Manual