Laurel Laureate Process & Ratio Panel Meter

The Laurel Laureate™ process & ratio panel meters are a digital, cost-effective solution for process signals such as 4-20 mA, 0-10V, or 0-5V which require zero and span adjustment for monitoring and control applications. Full-scale voltage input ranges from ±200 mV to ±600V and current ranges from ±2 mA to ±5 A are jumper selectable. All ranges are precalibrated at the factory, so that recalibration is not needed when changing ranges or signal conditioners. The 200.00 mV and 2.000 V ranges provide a high input impedance of 1 Gohm to minimize the load on the voltage signal.

The Laureate meter can be set to a ratio mode (or potentiometer follower mode) by making selections at the connector and in software. In this mode, the meter tracks a ratio of the applied excitation voltage and is unaffected by changes in the excitation voltage. This capability is used for resistive bridge sensors and voltage dividers, such as potentiometers which track wiper position.

Scaling is from -99,999 to +99,999 (five full digits) with any decimal point to display readings in engineering units, such as PSI. Three scaling methods are user selectable: scale and offset, two-point method, and system-level calibration using actual transducer signals.

An isolated 5, 10 or 24 Vdc isolated excitation output is standard to power transducers or two-wire transmitters. Ratiometric operation, which automatically compensates for changes in the applied excitation, is jumper selectable for applications, such as bridges, where the signal to be measured is proportional to the excitation level.

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 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.

The Laurel Laureate™ process & ratio panel meters are 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.