Laureate Digital Panel Meter | Process, Strain & Potentiometer Follower Meters

Laurel Electronics provides digital panel meters / controllers, totalizers, counters, loop-powered meters, temperature meters, for all types of transducers or process indication & control.

Laureate™ Process, Strain & Potentiometer Follower Meters
Panel Meters with scalable readout & control outputs

Features
0.2, 2, 20, 200 and 660 V ranges.	2, 20, 200 mA and 5 A ranges.
All ranges factory calibrated.	4 1/2 to 5 digit resolution.
Field scalable by front panel pushbuttons or computer for readout 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.
NEMA 4X (IP-65) 1/8 DIN case.	External controls for reset, meter hold, decimal points, and tare.
Choice of plug-in options for control and computer interface.	Certified to UL 3101-1, CAN/CSA-C22.2, EN 61010-1 (CE Mark).
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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		Isolated Excitation Supply
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. 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.		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		Advanced Meter Features
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.		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.
Interface Options	Rate & Nonlinear Curve Fit Options		Built-in Flexibility
Plug-in isolated analog output, dual setpoint controller and RS-232, RS-485 communications or BCD output boards can upgrade the Laureate from monitor to system interface and control.	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 240 data points can be input into a computer spreadsheet or text file by the user. The computer then calculates nonlinear segments, which are downloaded into the meter via RS-232.		The meters may be powered from 85-264 Vac and 90-370 Vdc, or optionally from 8-28 Vac and 9-37 Vdc. They are available with red or green LEDs. The DIN case meets NEMA 4X (IP-65) specifications from the front when panel mounted. Any setup functions and front panel keys may be locked out for simplified usage and security.
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Specifications
DC Voltage	DC Voltage Range	Resolution	Input Ohms	Error at 25°C ±1 count
	200.00 mV	10 µV	1 G	0.01% FS
	2.000 V	100 µV	1 G	0.01% FS
	20.000 V	1 mV	1 M	0.01% FS
	200.00 V	10 mV	1 M	0.01% FS
	660.0 V	100 mV	1 M	0.03% FS

DC Current	DC Voltage Range	Resolution	Input Ohms	Error at 25°C ±1 count
	2.0000 mA	0.1 µA	100	0.01% FS
	20.000 mA	1.0 µA	10	0.01% FS
	200.00 mA	10 µA	1	0.01% FS
	5.000 A	1.0 mA	0.01	0.04% FS

DC Voltage & Current
Display		A-to-D Conversion
Readout	5 digits, 7-segment, 14.2 mm (.56")	Technique	Concurrent Slope™ (Pat 5,262,780)
Color	Red or green LED	A-to-D Rate	60/s at 60 Hz, 50/s at 50 Hz
Range	-99999 to +99999 or -99990 to +99990 (count by 10 with rounding)	Output Update	56/s at 60 Hz, 47/s at 50 Hz
Indicators	Minus sign, 2 red LED lamps	Display Update	3.5/s at 60 Hz, 3/s at 50 Hz
Accuracy		Noise Rejection
Span Tempco	0.003% of reading/°C	CMR, DC to 60 Hz	130 dB
Zero Tempco	0.1 counts/°C	NMR at 50/60 Hz	90 dB with min filtering
Maximum Signal		Power
Max applied voltage	660 Vac for 20, 200 and 600 V ranges, 125 Vac for other ranges	Voltage, std.	85-264 Vac and 90-370 Vdc
		Frequency	DC or 49-440 Hz
Overcurrent protection	25x for 2 mA, 8x for 20 mA, 2.5x for 200 mA, 1x for 5 A	Voltage, opt.	8-28 Vac and 9-37 Vdc
		Power isolation	Safety-rated to 250 Vac, meter ground to earth ground, DC to 60 Hz, 4.2 kVp per High Voltage Test
Excitation Output		Connector Pin Assignments
5 Vdc	5 Vdc ±5%, 100 mA max
10 Vdc	10 Vdc ±5%, 120 mA max
24 Vdc	24 Vdc ±5%, 50 mA max
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
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Application Examples

Potentiometer Application

In potentiometric (or pot 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 output.

\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

Testing with peak detection

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.
Lauerate Powering two-wire transmitters

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.

Testing with peak detection

Linearizing non-linear inputs

Rate from successive readings

The Laureate DC meter with the Extended main board option allows exceptionally accurate custom curve linearization. For setup, up to 240 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.

One application, as illustrated, is the readout of volume of irregularly shaped tanks based on measured liquid level or pressure. Altimeters and thermistors are further applications.

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.

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FLW, Inc - 3505 Cadillac Ave - Bldg E - Costa Mesa, CA. - 92626 - USA - Ph (714) 751 - 7512 - Fax (714) 751 - 0213