DataLoop™ LI25 Level Controller
Instruction Manual
MN301034 rev D
27
Math Functions
(
lnEAr
,
SquAr
,
ProGE
,
Cutof
)
The LI25 SERIES provides a number of math functions to condition outputs from
linear and non-linear transmitters.
Linear (
lnEAr
)
Meters are set up at the factory for linear function. The linear function provides a
display that is linear with respect to the input signal.
Square Root (
SquAr
)
The square root function is used to linearize the signal from a differential
pressure transmitter and display flow rate in engineering units.
Programmable Exponent (
ProGE
)
The programmable exponent function is used to linearize the level signal in
applications using weirs and flumes and display flow rate in engineering units.
Upon selecting programmable exponent (Prog.E), the meter prompts entry of a
5-digit value between 0.5000 and 3.0000 as the exponent.
Low-Flow Cutoff (
CutoF
)
The low-flow cutoff feature allows the meter to be programmed so that the often-
unsteady output from a differential pressure transmitter, at low flow rates, always
displays zero on the meter.The cutoff value may be programmed from -99999 to
99999. Below the cutoff value, the meter will display zero. Selecting either square
root or programmable exponent will set the cutoff value to 0. Program the cutoff
value to -99999 to disable.
