Azbil MVC10A, User Manual

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Setting parameters and operating the local data setting device Azbil Corporation
4-18 Model: MVC10A/10F - Multivariable Air Flow Meter
Auto ranging function
This function enables the automatic setting of maximum flow rate value based on
the past flow rate since the power supply switch was turned on or the peak value
was reset. It is useful for setting the maximum flow rate value when installing this
instrument in a system whose flow rate is unknown.
Operation overview:
This device stores the maximum value of instantaneous flow rate and sets the
maximum flow rate that employs said maximum value as an 80% value in the
operation “Exe Auto Range.”
The preceding maximum flow rate value can be deleted by the operation “Del Peak
Value.”
Flow rate
Pre-execution range
Post-execution range
x 1.25 Maximum flow rate value
Time
Executing the auto ranging
Constantly calculating
the maximum value
• The adjustable range is 10 to 100% of the maximum flow rate value that can be
set depending on bore diameter. (For the details of maximum flow rate values that
can be set depending on bore diameter, refer to the Item “Setting the maximum
flow rate” under Subsection 4-8, “Initial settings.”)
• Maximum value of the flow rate is retained even after terminating the auto
ranging.
• Low flow cut values are not changed even after terminating the auto ranging.
(Example: When the percentage before auto ranging is 5%, the value will be 5%
of a new range after the auto ranging.)
• When reference temperature and pressure have been changed, since the details of
internal flow rate calculations are altered, delete the maximum flow rate value in
the operation “Del Rate Value.”