PD2-6060
Helios Large Display Dual-Input Meter Instruction Manual
51
Signal Input Conditioning (
Functn
)
The
Function
menu is used to select the input-to-output transfer function applied to the input signal:
linear, square root, programmable exponent, or round horizontal tank volume calculation. Multi-point
linearization is part of the linear function selection.
Meters are set up at the factory for linear function with 2-point linearization. The linear function provides a
display that is linear with respect to the input signal.
Square Root Linearization (
Square
)
The square root function is used to calculate flow measured with a differential pressure transmitter. The
flow rate is proportional to the square root of the differential pressure. Scale the meter so that the low
input signal (e.g. 4 mA) is equal to zero flow and the high input signal (e.g. 20 mA) is equal to the
maximum flow.
Programmable Exponent Linearization (
Prog E
)
The programmable exponent function is used to calculate open-channel flow measured with a level
transmitter in weirs and flumes. The flow rate is proportional to the head height. Scale the meter so that
the low input signal (e.g. 4 mA) is equal to zero flow and the high input signal (e.g. 20 mA) is equal to the
maximum flow. This method works well for all weirs and flumes that have a simple exponent in the flow
calculation formula. For weirs and flumes with complex exponents it is necessary to use a strapping table
and the 32-point linearization of the meter.
Multi-Point Linearization (
Linear
)
Meters are set up at the factory for linear function with 2-point linearization. Up to 32 linearization points
can be selected for each channel under the linear function. The multi-point linearization can be used to
linearize the display for non-linear signals such as those from level transmitters used to measure volume
in odd-shaped tanks or to convert level to flow using weirs and flumes with complex exponent.
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