Laureate™ Process, Strain &
Potentiometer Follower Meter
Digital panel meter /
controllers with scalable readout
& control outputs
for process, strain, pressure, level, flow, 4-20 mA signals & more.
Features
0.2, 2, 20, 200 and 300V ranges.
2, 20, 200 mA and 5A ranges.
All ranges factory calibrated.
4 1/2 to 5 digit resolution.
Scalable via front panel
pushbuttons or computer for display in engineering units.
Span adjust from 0 to ±99,999
Zero adjust from -99,999 to
+99,999
Peak value display and auto-tare.
Up to 60 conversions per second.
Selectable fixed right-hand zero
with rounding.
5, 10 or 24 Vdc transducer
excitation supply.
Ratiometric compensation for
variations in excitation voltage.
External controls for reset,
meter hold, decimal points, and tare.
Certified to UL 61010C-1 (UL mark), EN 61010-1 (CE mark),
and RoHS.
Description
Laureate
digital process and strain panel meters are a cost-effective solution to a wide variety of
monitoring and control applications which require a scalable readout from strain gauges or
from process signals such as 4-20 mA, 0-5 V or 0-10 V. They are also ideal for use in
potentiometer follower applications, where the transducer output is a changing resistance.
Scalable to Five Full Digits
The display may be
scaled to five full digits from -99,999 to +99,999 from the front panel to read directly
in engineering units
, such as
PSI. Three scaling methods are selectable: scale and offset, two-point method, and
system-level calibration using actual transducer signals. All ranges are precalibrated at
the factory, so that recalibration is not needed when changing ranges or signal
conditioners.
With the Laureate process meter,
strain gauges with a 20 mV output can be
scaled to display up to 10,000 counts, while outputs of 200 mV can be scaled to 99,999
counts.
With the Laureate load cell meter, strain gauges
with a 20 mV output can be scaled to the full 99,999 counts.
Isolated Excitation Supply
5, 10, and 24 Vdc
isolated excitation outputs are standard to power strain gauge bridges and 4-20 mA
transmitters, eliminating the need for an external supply. When powering strain gauges or
potentiometers, the 5 or 10 Vdc excitation is monitored by the meter to eliminate errors
caused by excitation voltage variations.
Fast Read Rate and Signal Filtering
The displayed readings
and the data outputs can be separately selected to be either unfiltered or filtered.
An unfiltered
selection updates after each conversion for fastest response, up to 60/sec, while
integrating the input signal over a full power cycle. Fast read rate provides true peak
readings and aids in control applications.
A batch-average
filter selection averages each 16 conversions for an update every 1/4 sec.
An adaptive moving
average filter selection provides a choice of 8 time constants from 80 ms to 9.6
s. When a significant change in signal level occurs, the filter adapts by briefly
switching to the shortest time to follow the change, then reverts back to its selected
time constant. Another choice is Auto, which provides an automatic time constant selection
based on the signal noise characteristics.
Advanced Meter Features
Auto-tare allows the display to be zeroed for any input signal. This is
normally achieved by applying a switch closure or logic signal at the rear connector. The
tare value is stored in non-volatile memory and is retained when power is removed.
Peak value of the input
signal is automatically captured and may be displayed via a front panel pushbutton command
or control signal at the rear connector. Other controls via the rear connector include
meter hold, meter reset, peak reset, and decimal point selection.
An Extended Laureate
computer board can display rate based on successive readings. It also allows exceptionally
accurate custom curve linearization, for example to read out liquid volume or rate of flow
in a horizontal cylindrical tank based on level reported by a 4-20 mA transmitter. For
setup, up to 180 data points can be input into a
computer spreadsheet or text file by the user. The computer then
calculates spline-fit segments, which are downloaded into the meter via RS-232.
Built-in Flexibility &
Safety
Laureates may be powered from
95-240 Vac ±10% or optionally
from 12-30 Vac or 10-48 Vdc. They are available
with red or green LEDs. They are housed in a
1/8 DIN case that meets NEMA 4X (IP65) specifications from the front
when panel mounted. Any setup functions and front panel keys may be
locked out for simplified usage and security.
Specifications
DC Voltage
DC
Voltage Range
Resolution
Input
Ohms
Error
at 25°C
±2 counts
±200.00
mV
2.000 V
20.000 V
200.00 V
600.0 V *
300.0 V
0-10V,
0-20 mA, 4-20 mA (jumper selectable)
2 mA at 10V (5 kOhm load), 12V at 20 mA (0-60 ohm load)
Zero and full scale adjustable from -99999 to +99999
12 bits (0.025% of full scale)
250V rms working, 2.3 kV rms per 1 min test
Dual Contact Relay Outputs (optional)
Relay
Type
Load Rating
Isolation
Form C
8A at 250 Vac or 24 Vdc
250V rms working, 2.3 kV rms per 1 min test
Dual Solid State Relay Outputs (optional)
Relay Type
Load Rating
Isolation
SPST, normally open,
Form A
120 mA at 130 Vac or 170 Vdc, 28 ohms series resistance
250V rms working, 2.3 kV rms per 1 min test
Serial Data I/O (optional)
Board Selections
Protocols
Data Rates
Digital Addresses
Isolation
RS232, RS485, Modbus RS485
Modbus RTU, Modbus ASCII, simpler Laurel ASCII
300 to 19200 bps
247 (Modbus), 31 (Laurel ASCII),
250V rms working, 2.3 kV rms per 1 min test
0°C to
60°C
-40°C to 85°C
95% at 40°C, non-condensing
NEMA-4X (IP-65) when panel mounted
Application Examples
Potentiometer
Application
In potentiometric (or
potentiometer follower) applications, the signal from a sliding contact
voltage divider can be converted to engineering units such as position,
level or percentage. By operating in a ratiometric mode, the meter will
remove any effects caused by variations in the excitation supply.
For use with a 1 kohm potentiometer, the
recommended applied excitation voltage is 10 V, and a 2 kohm resistor should be
placed in series with the excitation output and excitation return leads. This will allow
the meter's 2.0000 V scale with a high input impedance of 1 Gohm to be used.
Powering two-wire transmitters
The isolated 24 Vdc, 50 mA excitation output, which is standard with all Laureate meters,
is ideal for powering two-wire, 4-20 mA transmitters. The same two wires are used to apply
voltage and carry the output current. Inside the meter, the 4-20 mA current is dropped
across a 10 ohm resistor and sets up a 40-200 mV
voltage, which is then sensed by the meter and scaled to engineering units.
Testing with peak detection
Destructive testing is an ideal application for the Laureate strain meter. Peak readings
are automatically captured at rates up to 60 per second, while the display updates at a
legible 3.5 readings per second. The peak reading can be recalled at the push of a button
or be transmitted via RS-232 or RS-485. The meter
provides isolated 10 Vdc power for up to four (4) the strain gauges and can be scaled to
read out directly in engineering units from -99,999 to +99,999.
Custom
curve linearization
The Laureate DC meter with the Extended main board option allows exceptionally
accurate custom curve linearization. For setup, up to 180 data points can be entered into
a spreadsheet. The system then creates multiple non-linear spline-fit segments, which
provide much better accuracy than linear segments.
Illustrated, is the
readout of volume of irregularly shaped tanks based on measured liquid level or pressure.
Altimeters and thermistors are further applications.
Rate from
successive readings
The Extended computer board allows the display of rate based on successive
readings, for instance flow rate based on changes in liquid level or static pressure in a
tank.
In the above illustration, the
meter displays the rate in gallons at which a horizontal tank is being emptied. The input
to the meter can be nonlinear, since only the linearized readings are compared for the
determination of rate.
Ordering Guide Laureate™ Process, Strain & Potentiometer Follower Meters Click
on the radio buttons to build a model number with pricing.