Laurel Electronics Laureate Meters User Manual

LAUREL

ELECTRONICS, INC.

Key Features of Meter Linearizing

•

Applicable to Laureate™ process, strain gauge, load cell meters, frequency /
rate meters, and totalizers

•

Easy programming using custom nonlinear curve fits

•

Improves accuracy of low-cost transducers

•

Extends transducer operating range on high and low ends

•

Solves application problems involving non-linear relationships

•

Included with Extended versions of Laureate digital panel meters, counters
and timers

•

Easy setup by entering data points into a computer spreadsheet, or typing in
desired readings for actual signal inputs.

•

Exceptional accuracy from 0.1% to 0.01% of full scale with few data points,
made possible by curvilinear spline fits.

Description

Custom curve linearization is a feature available with the

Extended option version of all Laureate digital panel meters,
counters and timers, excluding only the temperature meter,
which already has built-in linearization curves.

Benefits: Custom curve linearization can provide exceptional
accuracy from low cost transducers of these are repeatable. It
can extend the working range of transducers on their high and
low ends. It can also solve special application problems where
there is a non-linear relationship between the input and the
desired readout.

Implementation: Linearizing is implemented in the form of
20 nonlinear spline-fit segments, which provide much better
accuracy than a larger number of straight line segments. The
typical error will be from 0.1% to 0.01% of full scale, depending
on the number of data points used for setup, the error in the data
points, and the severity of non-linearities or discontinuities.

Easy Setup: Setup of a Laureate Linearizing Process Meter
requires an external PC, which is connected to the meter via
RS232 or USB cable, and utilizes linearizing software furnished
by Laurel Electronics. To download, go to our Software Down­load web page. A serial communications board is required, but

Laureate™ Meters with

Custom Curve Linearization

can be removed from the meter following setup. Three meter
programming methods are offered:

•

Spreadsheet Method: Data points consisting of the input
signal in Volts or Amps and the desired reading are entered
into an Excel spreadsheet or into a text file using a space,
comma or tab as the delimiter. There can be up to 180 data
points. Laurel's software then calculates 20 spline-fit seg­ments and downloads their coefficients into the meter.

•

Actual Input Method: The meter is hooked up to the actual
signal source, and the user enters the desired readings for
different signal levels. There can be up to 180 input / reading
combinations. Laurel's software then calculates 20 spline-fit
segments and downloads their coefficients into the meter.
This method automatically compensates for any errors in the
transducer.

•

Polynomial Method: The mathematical formula relating the
input to the output is entered into the computer, which then
uses this data to calculate the spline-fit segments. This
method is ideal if the mathematical relationship is knows, for
example to calculate the contents of a tank based on the
known geometry of the tank.

Application Examples

•

Thermistors and other sensors whose output is a non-linear
changing resistance.

•

Altimeters, since the relationship between pressure and
altitude is non-linear.

•

Rate of ascent based on successive altimeter readings.

•

Volume of irregularly-shaped tanks, such as horizontal
cylinders, based on measured liquid level or liquid pressure at
the base of the tank.

•

Fine-calibration of linear transducers, since even nominally
linear transducers will have nonlinear components.

•

Extending the working range of transducers, since many
transducers become nonlinear at their low and high ends.

Compensating for inaccuracy of low-cost transducers.

LAUREL

ELECTRONICS INC., 3183-G Airway Ave., Costa Mesa, CA 92626, USA • Tel [phone] • www.laurels.com 1

Measuring tank volume

The Extended Laureate process meter can display the volume of
irregularly shaped tanks based on the static pressure at the base
of the tank. An example is a cylindrical tank lying on its side. The
tank can be tilted to facilitate drainage, as illustrated.

Ordering Guide

Create a model a model number in this format: L30000P, IPC

Main Board Compatible Signal Conditioner

L3 or L4 DC, P, SG, WM

L7 or L8 FR, VF

Main Board

Power

(isolated)

Relay Output

(isolated)

Analog Output

(isolated)

Digital Interface
(isolated)

L3 Extended DPM Main Board, Green LEDs.
L4 Extended DPM Main Board, Red LEDs.
L7 Extended Counter Main Board, Green LEDs.
L8 Extended Counter Main Board, Red LEDs.

Note: Extended capability is required for custom curve linearization or for display of

time rate of change, such as flow rate from changing tank level or acceleration from
changing speed. Not applicable to temperature meters.

0 Isolated 85-264 Vac
1 Isolated 12-32 Vac or 10-48 Vdc

0 None
1 Two 8A Contact Relays
2 Two 120 mA Solid State Relays
3 Four 8A Contact Relays
4 Four 120 mA Solid State Relays

0 None
1 Isolated 0-20 mA & 0-10 V
2 Dual isolated output, 4-20 mA, 0-20 mA, 0-10V

0 None
1 RS232
2 RS485 (dual RJ11 connectors)
4 RS485 Modbus (dual RJ45 connectors)
5 USB
6 USB-to-RS485 device server
7 Ethernet
8 Ethernet-to-RS485 device server

Signal Input

(isolated)

LAUREL

DC Volts
DCV1 ±200.00 mV
DCV2 ±2.0000 V
DCV3 ±20.000 V
DCV4 ±200.00 V
DCV5 ±300.0 V

DC Amps
DCA1 ±2.0000 mA
DCA2 ±20.000 mA
DCA3 ±200.00 mA
DCA4 ±5.000 A

Process Signals (e.g., 4-20 mA, 0-5 V)
P Field Scalable. Default scaling is 4-20 mA = 0-100.00

Strain Gage, Potentiometer (4-wire ratio)
SG Field scalable. Default scaling is 0-200 mV = 0-100.00

Note: The same DC signal conditioner board can be user-configured for DC Volts,

DC Amps, process, or strain. Precalibrated in EEPROM for all DC Volt and DC Amp
ranges listed.

ELECTRONICS INC., 3183-G Airway Ave., Costa Mesa, CA 92626, USA • Tel [phone] • www.laurels.com 2