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The Laureate™ Scale Meter is compact, inexpensive, and extremely accurate digital panel meter with special firmware for weighing applications. It is available with the Laureate load cell or DC signal conditioner board. If you do not need the special weighing firmware, consider using the Laureate load cell meter or Laureate process meter.
The load cell signal conditioner board accepts full-scale ranges of 20, 50, 100, 250 and 500 mV with 4- or 6-wire load cell hookup to display up to 99,999 counts or 999,990 counts with a selectable dummy right zero. With 4 wires, the meter operates in a ratiometric mode to eliminate errors due to supply variations. With 6 wires, it also compensates for resistance of the excitation wires, thereby allowing long cable runs. The built-in, isolated excitation supply can power up to four 350-ohm load cells in parallel at 5 Vdc or 10 Vdc.
The DC signal conditioner board can used in lieu of the load cell signal conditioner board, be set to ratiometric operation, and be used with ther meter's 5 Vdc or 10 Vdc excitation. It's most sensitive full-scale range is ±200 mV with 10 µV resolution, while the load cell signal conditioner board offers most sensitive ranges of ±20 mV and ±50 mV, both with 1 µV resoltuion. Meters with both boards offer an accuracy of 0.01% of full scale ± 2 counts.
Display & Setpoint Functions for Weighing Applications
Easy scale calibration is achieved using a simple two-point calibration method. First, the desired LO IN reading is set to 0, and the desired HI IN reading is set to a desired value. With no weight on the scale, a button is pushed for LO IN. With a known weight on the scale, that button is pushed again for HI IN. The meter then automatically computes scale and offset for readout up to five digits in weight units.
Fast read rates to 60/sec are provided for weigh-in-motion systems, setpoint control, and computer interface. Concurrent Slope (Pat 5,262,780) is a method of analog-to-digital conversion which allows up to 60 conversions per second while integrating the input signal over a full AC line cycle.
An adaptive digital filter can be set for time constants from 17 ms to 9 s, yet responds rapidly to a change in input signal level exceeding a threshold value. The meter can also automatically select the best filter setting for maximum noise rejection and minimum response time. Peak and valley capture are standard.
Designed for flexibility. Optional plug-in boards for communications and control include WiFi and serial communication boards, dual or quad relay boards, and an isolated analog output board. Laureates may be powered from 85-264 Vac or optionally from 12-32 Vac or 10-48 Vdc. The display is available with red or green LEDs. The 1/8 DIN case meets NEMA 4X (IP65) specifications from the front when panel mounted. Any setup functions and front panel keys can be locked out for simplified usage and security. A built-in isolated 5, 10, or 24 Vdc excitation supply can power transducers and eliminate the need for an external power supply. All power and signal connections are via UL / VDE / CSA rated screw clamp plugs..
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In 4-wire DC or load cell 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. |
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In 6-wire load cell 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. |
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The DC signal conditioner board can also be utilized to accept preconditioned 4-20 mA or 0-10 V scale signals. In two-wire 4-20 mA transmitter connection, the same two wires are used to apply voltage and carry the output current. |
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In a repetitive fill operation (as illustrated by example), a setpoint offset of -50 allows a shutoff setpoint to be set for 1000 and actual shutoff to occur at 950 if it is known that 50 units will still flow following shutoff. An offset can also be applied to emptying operations. |
| Full-Scale Input | Input Impedance | Zero Adjust | Span Adjust | Error at 25°C |
|---|---|---|---|---|
| ±20.00 mV | ||||
| ±50.00 mV | -99,999 | 0 | ||
| ±100.00 mV | 1 GΩ | to | to | 0.01% FS |
| ±250.00 mV | +99,999 | ±99,999 | ± 2 counts | |
| ±500.00 mV |
| Full-Scale Input | Input Impedance | Zero Adjust | Span Adjust | Error at 25°C |
|---|---|---|---|---|
| ± 200.00 mV | 1 GΩ | |||
| ± 2.0000 V | 1 GΩ | -99,999 | 0 to | 0.01% FS |
| ± 20.000 V | 10 MΩ | to +99,999 | ±99,999 | ± 2 counts |
| ± 20.000 mA | 10 Ω |
| Display | |
|---|---|
| Readout | 5 LED digits, 7-segment, 14.2 mm (.56"), red or green |
| Range | -99999 to +99999 |
| -999990 to +999990 (with fixed selectable right-hand zero) | |
| Rounding | Count by 1, 2, 5, 10, 20, 50, 100 |
| Indicators | Four LED lamps |
| Accuracy | |
| Error at 25°C | 0.01% FS ± 2 counts |
| Span tempco | 0.0015% of reading/°C |
| Zero tempco | 0.1 µV/°C (use auto-zero when temperature changes) |
| Calibration Method | 2 points using zero weight and known weight |
| Noise Rejection | |
| CMR, DC to 60 Hz | 130 dB |
| NMR at 50/60 Hz | 90 dB with min filtering |
| A-to-D Conversion | |
| Technique | Concurrent Slope (Pat 5,262,780) |
| A-to-D rate | 60/s at 60 Hz, 50/s at 50 Hz |
| Output update | 56/s at 60 Hz, 47/s at 50 Hz |
| Display update | 3.5/s at 60 Hz, 3/s at 50 Hz |
| Power Supply Boards (one required) | |
| Voltage, standard | 85-264 Vac or 90-300 Vdc |
| Voltage, optional | 12-32 Vac or 10-48 Vdc |
| Frequency | DC or 47-63 Hz |
| Power consumption (typ. with four 350Ω load cells at 10V) | 2.4W @ 120 Vac, 2.7W @ 240 Vac, 2.5W @ 10 Vdc, 2.6W @ 20 Vdc, 2.75W @ 30 Vdc, 3.0W @ 40 Vdc, 3.35W @ 48 Vdc |
| Power Isolation | 250V rms working, 2.3 kV rms per 1 min test |
| Excitation Output (standard) | |
| 5 Vdc | 5 Vdc ± 5%, 100 mA |
| 10 Vdc | 10 Vdc ± 5%, 120 mA |
| 24 Vdc | 24 Vdc ± 5%, 50 mA |
| Output Isolation | 50 Vdc to meter ground |
| Analog Output Board (one optional) | |
| Output levels | 4-20 mA, 0-20 mA, 0-10V |
| Current compliance | 2 mA at 10V ( > 5 kΩ load) |
| Voltage compliance | 12V at 20 mA (< 600 Ω load) |
| Scaling | Zero and full scale adjustable from -99999 to +99999 |
| Resolution | 16 bits (0.0015% of full scale) |
| Isolation | 250V rms working, 2.3 kV rms per 1 min test |
| Relay Output Boards (one optional) | |
| Dual magnetic relays | 2 Form C, 8A at 250 Vac or 24 Vdc, 0.3A at 250 Vdc, resistive load |
| Quad magnetic relays | 4 Form A (NO), 8A at 250 Vac or 24 Vdc, 0.3A at 250 Vdc, resistive load |
| Dual solid state relays | 2 Form A (NO), 120 mA at 140 Vac or 180 Vdc, resistive load |
| Quad solid state relays | 4 Form A (NO), 120 mA at 140 Vac or 180 Vdc, resistive load |
| Relay commons | Isolated commons for dual relays or each pair of quad relays |
| Relay isolation | 250V rms working, 2.3 kV rms per 1 minute test |
| Relay latching modes | Latching or non-latching |
| Relay active modes | Active on or off, active high or low |
| Hysteresis modes | QA passband mode, split hysteresis, span hysteresis |
| Communication Boards (one optional) | |
| Board selections | RS232, RS485 with dual RJ11 connectors, RS485 with dual RJ45 connectors, USB, USB-to-RS485 gateway, WiFi with built-in antenna plus USB & RS485, WiFi with external antenna plus USB & RS485 |
| Protocols | Modbus RTU, Modbus ASCII, Modbus TCP (Ethernet), Laurel ASCII |
| Digital addresses | 247 (Modbus), 31 (Laurel ASCII), |
| Isolation | 250V rms working, 2.3 kV rms per 1 min test |
| Environmental | |
| Operating temperature | 0°C to 55°C standard, -40°C to 70°C with -X option |
| Storage temperature. | -40°C to 85°C |
| Relative humidity | 95% at 40°C, non-condensing |
| Protection | NEMA-4X (IP-65) when panel mounted |
The Laureate weight meter power all four 350 ohm load cells of the scale with its 10 V, 120 mA isolated excitation output. Six-wire connection eliminates the effects of lead resistance and allows long cable runs from the control room to the scale.
The five-digit meter can be scaled to display truck weight up to 99,999 lbs with 1 lb resolution or 999,990 lbs with 10 lb resolution. Accuracy is 0.01% of full scale at 25°C. To avoid the effects of system-level noise, different filter settings as well as "count by" of 1, 2, 5, 10, 20, 50 or 100 with rounding are selectable.
To read out net weight of the load, the truck can first be weighed empty, and this weight can be entered as tare at the push of a button in an auto-tare mode. Or the nominal tare value of the truck can be entered manually. Display of net weight or gross weight is at the push of a button. The gross weight and net weight can be alarmed, be transmitted to a computer via RS232 or RS485, or be transmitted via a 4-20 mA analog signal.
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