Standard 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 or valley display and auto-tare
• Up to 60 conversions per second
• Selectable fixed right-hand zero with rounding
• External controls for reset, meter hold, decimal points, and tare
• Universal AC power, 85-264 Vac
• 5, 10 or 24 Vdc excitation supply
• Ratiometric compensation for variations in excitation voltage
• External controls for reset, meter hold and decimal points
• NEMA 4X, 1/8 DIN case
• Certified to UL 61010C-1 (UL mark), EN 61010-1 (CE mark), and RoHS)
  Options:
• Low voltage power: 10-48 Vdc or 12-32 Vac
• 2 or 4 output relays, electromechanical or solid state
• Analog output: Isolated, 4-20 mA, 0-20 mA, 0-10V, -10 to +10V
• Serial communications: RS232, RS485, Modbus RS485, USB, USB-to-RS485 converter

Laureate™ digital process and strain panel meters are a cost-effective solution to monitoring and control applications which require zero and span adjustment for process signals such such as 4-20 mA, 0-5 V, 0-10 V, or strain gauges. The meters are also suitable for potentiometer follower applications, where the transducer output is a changing resistance.

The display is scalable 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 with a 4-wire ratiometric connection, while 200 mV outputs of  can be scaled to display up to 99,999 counts. For higher sensitivity, 20 mV signals can be scaled to 99,999 counts with a 4- or 6-wire connection using the Laureate load cell meter.

An isolated 5, 10 or 24 Vdc isolated excitation output is standard to power external transducers and transmitters. Up to 120 mA is provided at 10V to power four 350 ohm load cells in parallel. When powering strain gauges, load cells or potentiometers, the excitation output is monitored by the meter to eliminate errors due to voltage variations.

High read rates at up to 60 or 50 conversions per second while integrating the signal over a full power cycle are provided by Concurrent Slope (US Pat 5,262,780) analog-to-digital conversion. High read rates are ideal for peak or valley capture, real-time computer interface, and control.

Peak and valley values are automatically captured. These may be displayed via a front panel pushbutton command or control signal at the rear connector, or be transmitted as serial data.

Digital filtering is selectable for electrically noisy environments, including a batch averaging filter and an adaptive moving average filter which provides a choice of 8 time constants from 80 ms to 9.6 s. When a significant change in signal level occurs, that filter adapts by briefly switching to the shortest time to follow the change, then reverts back to the selected time constant. In a selectable Auto filter mode, the filter time constant is automatically selected based on detected signal noise.

Auto-tare allows the display to be zeroed for any input signal 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.

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.

Designed for flexibility. Optional plug-in boards for communications and control include an analog output board, dual or quad relay boards, and serial communications boards. 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.

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.
  

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.

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.

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.