Badger Meter Vortex Meters - Manual (Page 21)

Page 19
Integrated RTD - If the meter is supplied with an integrated RTD, it is typically the best choice
for the “Process Temperature Source”. The integrated RTD is embedded in the meter hous-
ing and can provide real-time process temperature information. With real-time temperature
information, the meter can compensate for mass flow and standard flow measurements when
the temperature changes. If the process temperature displays 999F when using the integrated
RTD, the RTD has failed.
User Defined - The “User Defined” temperature source can be selected to specify a constant
process temperature. If this temperature source is selected, the temperature value entered in
the “User Defined” temperature field is used as the process temperature.
When the user defined temperature source is selected, the meter cannot compensate mass
flow or standard flow measurements when the temperature changes.
steam Table - The “Steam Table” temperature source can only be selected on steam meters.
When this temperature source is selected, the meter uses the process pressure and a saturat-
ed steam table to determine the process temperature. This function assumes saturated steam
and will not accurately calculate the temperature of superheated steam.
NOTE: It is important to note that the “Steam Table” cannot be selected as the process temperature source if
the “Steam Table” has already been selected as the process pressure source in the “Process Pressure”
dialog box.
Typical process Temperature and pressure source scenarios
For steam applications, it is typical for the internal RTD to be selected as the process tempera-
ture source and the “Steam Table” to be selected as the process pressure source. This allows
the meter to compensate for both temperature and pressure fluctuations without having a
pressure gauge. For gas applications, it is typical for the process temperature source to be the
internal RTD and a constant user defined value for the process pressure. This allows the meter
to compensate for temperature fluctuations.
process Temperature - This field displays the process temperature. The value of this field is
dependent on the source of the process temperature. If the process temperature source is set
to integrated RTD, this field will display the temperature measured by the selected device. If
the process temperature source is set to “User Defined”, then this field will be the value of the
“User Defined” temperature field. If the process temperature source is set to “Steam Table”,
then this field is calculated from a saturated steam table based on the process pressure. This
field is read only.
process Temperature unit - This field specifies the unit of the process temperature. To
change the unit, select a new unit from the drop down menu and then click the Write button.
User Defined Temperature - This field allows the user to enter a constant process tempera-
ture. However, this temperature is only used when “User Defined“ is selected as the process
temperature source. The unit for this field is F°.
NOTE: Save the changes to EEPROM and put the meter in-service after making changes.