Laureate™ Process, Strain & Potentiometer Follower Meter

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 system use. Optional plug-in boards for communications and control include Ethernet and other 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. All power and signal connections are via UL / VDE / CSA rated screw clamp plugs.