EFLOW EF-Series - History Points

Using the EF-Series Unit
2-4 Rev 2/01
Instantaneous Rate Calculations
The instantaneous value of the flow extension is used with the previous recalculation period’s Integral
Multiplier Value (IMV) to compute the instantaneous flow rate. The IMV is defined as the value
resulting from the calculation of all other factors of the flow rate equation not included in the Integral
Value (IV). The IV is defined as the flow extension. The instantaneous flow rate is used with the
volumetric heating value to compute the instantaneous energy rate.
Flow and Energy Accumulation
The averages of the differential and static pressure, temperature, and flow extension are used with the
flow time to compute the flow and energy over the recalculation period. The flow and energy are then
accumulated and stored at the top of every hour. At the configured contract hour, the flow and energy
are then stored to the Daily Historical Log and zeroed for the start of a new day.
2.3.2 History Points
A total of fifteen history points may be logged and accessed in the EF-Series unit. The first eight are
pre-configured for flow metering history and cannot be changed. They are as follows:
♦ Flowing Minutes Today (Accumulate archive type)
♦ Differential Pressure (Average)
♦ Static or Line Pressure (Average)
♦ Temperature (Average)
♦ IMV, Integral Multiplier Value, or C Prime (Average)
♦ Pressure Extension or IV, Integral Value (Average)
♦ Instantaneous Flow (Accumulate)
♦ Instantaneous Energy (Accumulate)
History Point 2, History Point 3, History Point 4, and History Point 6 are all set up as an Average
Archive Type that employs one of the following techniques:
♦ Flow dependent time-weighted linear averaging (default selection)
♦ Flow dependent time-weighted formulaic averaging.
♦ Flow-weighted linear averaging.
♦ Flow-weighted formulaic averaging.
For the history points above, the averaging technique is selected by using ROCLINK. In the Meter
menu, select Setup, then select Inputs. In the Inputs screen, select the desired Averaging Technique.
The selected technique will then be applied to the meter inputs.
The seven user-configurable history points may be configured as described in the ROCLINK User
Manual (see Configure - History).