Laurel

Laureate™ Load Cell & Microvolt Panel Meter

(20 mV - 500 mV full-scale ranges, 4- or 6-wire connection)
Features
  • 20, 50, 100, 250 & 500 mV ranges.
  • Zero from -99,999 to +99,999
  • Selectable fixed zero or active least significant digit.
  • Ratiometric operation cancels variations in excitation supply.
  • Peak value display standard.
  • AC or DC powered.
  • NEMA 4X (IP-65) front panel, 1/8 DIN case.
  • Certified to UL 3101-1, CAN/CSA-C22.2, EN 61010-1 (CE Mark).
  • 5-digit resolution with span from 0 to ± 99,999
  • Isolated 10 Vdc supply to power up to four 350 ohm load cells.
  • 4- or 6-wire hookup.
  • Up to 60 conversions per second.
  • Auto-tare with tare value stored in memory
  • Green or red display.
  • Optional dual relays, 4-20 mA & 0-10 V analog output, RS-232/485 I/O, parallel BCD output, and low voltage power.
Built-in Excitation
An isolated 10 Vdc excitation supply can provide up to 120 mA of current to power up to four 350-ohm load cells in parallel. The meter operates in a ratiometric mode to eliminate errors due to supply variations. When excitation sense inputs are used in 6-wire connection, the meter compensates for variation in resistance of the transducer leads, thereby allowing long cable runs.
Fast Read Rate plus Peak Capture
All Laureate meters use Concurrent Slope (Pat 5,262,780) analog-to-digital conversion, which allows up to 60 conversions per second, while integrating the signal over a full power cycle. High read rate is ideal for peak value capture and for real-time computer interface and control. Peak capture is standard
Selectable 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.

Easy Scaling
All Laureate DC, process and load cell meters allow easy setting of scale and offset by either of two methods.

With the coordinate reading method, the meter reads the high and low signal values, and the user enters the desired high an low reading values. The meter then calculates the span multiplier and offset. This method is ideal if an external calibration reference is available.

With the manual coordinate method, the user enters the high and low input values in Volts plus the desired high and low reading values. This method is suitable if an no external calibration reference is available.
Auto-tare
For weighing applications, auto-tare is standard. Auto-tare can set the displayed value to zero to subtract the weight of an empty container. Auto-tare may be controlled by an external pushbutton contact closure or logic signal through an input on the power supply connector. The tare value is stored in memory. Additional capabilities for weighing applications are provided by the Laureate weight / scale meter, as described in a separate web page.
Other Features & Options
Plug-in isolated analog output, dual setpoint controller and RS-232/485 commu- nications or BCD output boards can upgrade the Laureate from a stand-alone monitor to system interface and control. All Laureates meet NEMA 4X (IP-65) standards for high pressure washdown when panel mounted. All connections are via safety-rated screw-terminal connectors.

Specifications

DC Microvoltmeter Inputs Input Range
mV
Resolution Error at 25°C
±20.000 1.0 µV  
±50.000 2.5 µV  
±100.00 5.0 µV 0.01% FS
±250.00 12.5 µV ±1 count
±500.00 25 µV  
 
Load Cell Inputs Full-Scale
Input, mV
Zero
Adjust
Span
Adjust
Error at 25°C
±20.000 -99,999
to
+99,999
0 to
±99,999
0.01% FS
±1 count
±50.000
±100.00
±250.00
±500.00

DC Microvolts & Load Cell

Accuracy Noise Rejection
Span Tempco 0.0015% of reading/°C
CMR, DC to 60 Hz
130 dB
Zero Tempco 0.1 µV/°C NMR at 50/60 Hz 90 dB with min filtering
A-to-D Conversion Display
Technique Concurrent Slope™ (Pat 5,262,780) Readout 5 digits, 7-segment, 14.2 mm (.56")
A-to-D Rate 60/s at 60 Hz, 50/s at 50 Hz Color Red or green LED
Output Update 56/s at 60 Hz, 47/s at 50 Hz Range -99999 to +99999 or -99990 to +99990 (count by 10 with
rounding)
Display Update 3.5/s at 60 Hz, 3/s at 50 Hz Indicators Minus sign, 2 red LED lamps
Power Excitation Output
Voltage, std 85-264 Vac and 90-370 Vdc 5 Vdc 5 Vdc ±5%, 100 mA max
Voltage, opt 8-28 Vac and 9-37 Vdc 10 Vdc 10 Vdc ±5%, 120 mA max
Frequency DC or 49-440 Hz 24 Vdc 24 Vdc ±5%, 50 mA max
Power isolation Safety-rated to 250 Vac, meter ground to earth ground,
DC to 60 Hz, 4.2 kVp per High Voltage Test
Output isolation 50 Vdc to meter ground
Environmental
Operating Temperature 0°C to 55°C
Storage Temperature -40°C to 85°C
Relative HumidityProtection NEMA-4X (IP-65) when panel mounted

Load Cell Meter Connections

Laureate Load Cell Meter 4 Wire Connections
In 4-wire connection, the excitation and sense lines are tied together. The meter can make ratiometric corrections for supply voltage variations, but not compensate for variations in lead resistance. This connection is often used with short cable runs.
Laureate Load Cell Meter 6 Wire Connections
In 6-wire connection, the sense lines are separate from the excitation lines, thereby eliminating effects due to variations in lead resistance. This allows long cable runs in outdoor environments with temperature extremes.
Laureate Load Cell Meter Large Scale Connections
For large scales, up to four 350 ohm load cells can be powered by a single Laureate, whose excitation output is rated 120 mA at 10 V. The excitation and sense points of the four bridges are connected in parallel through a summing box.
Sample Load Cell Meter Applications
Laureate Sample Load Cell Meter Applications Auto-Tare

To read the net weight of an object, the empty container is first weighed, and an external button is pushed to zero out the display. The meter will then read net weight when an object is added to the empty container. The tare value is stored in memory for subsequent readings.

Laureate Sample Load Cell Meter Applications Determining Volume Using Load Cells

An easy way to determine volume of an irregularly shaped tank with no need for linearizing is to weigh the tank using load cells. The meter will automatic- ally tare out the weight of the empty tank and then scale the load cell signals to units of volume, such as gallons.

Laureate Sample Load Cell Meter Applications Peak Capture for Testing the Tensile Strength of Wire

Peak readings are automatically captured at rates up to 60 per second, while the display updates at a legible 3.5 per second. The peak reading can be recalled at the push of a button or be always displayed. It can also be transmitted to a computer via RS-232 or RS-485.

Purchase
5672 Bolsa Avenue Huntington Beach, CA 92649 - USA - Ph (714) 622-2000 - Fax (714) 622-2001