Laureate™ Custom Curve Linearizing Process Meter Panel Meter
(with easy programming for nonlinear curve fits)
- Able to handle nonlinear relationships between input signal and reading.
- Easy setup by entering data points into a computer spreadsheet, or typing in desired readings for actual signal inputs.
- 2, 20, 200 mA and 5 A input ranges.
- 5 digit resolution.
- Zero adjust from -99,999 to +99,999
- Up to 60 conversions per second.
- 5, 10 or 24 Vdc transducer excitation supply.
- NEMA 4X (IP-65) 1/8 DIN case.
- Linearized analog output option.
- Exceptional accuracy from 0.1% to 0.01% of FS using curvilinear spline fits.
- 0.2, 2, 20, 200 and 660 V ranges.
- All ranges factory calibrated.
- Span adjust from 0 to ±99,999
- Peak value display standard.
- Selectable fixed right-hand zero with rounding.
- Ratiometric compensation for variations in excitation voltage in pot follower applications.
- External controls for reset, meter hold, decimal points, and tare.
- Certified to UL 3101-1, CAN/CSA-C22.2, EN 61010-1 (CE Mark)
Setup of a Laureate Linearizing Process Meter requires an external PC, which is connected to the meter via an RS-232 cable, and utilizes linearizing software furnished by Laurel Electronics. To download, go to our Download Page. Three meter programming methods are offered:
Data points consisting of the input signal in Volts or Amps and the desired reading are entered into an Excel spreadsheet or into a text text file using a space, comma or tab as the delimiter. There can be from 2 to 240 data points. Laurel's software then calculates 20 spline-fit segments and downloads their coefficients into the meter.
Actual Input Method
The meter is hooked up to the actual signal source, and the user enters the desired readings for different signal levels. There can be from 2 to 240 input / reading combinations. Laurel's software then calculates 20 spline-fit segments and downloads their coefficients into the meter. This method automatically compensates for any errors in the transducer.
The mathematical formula relating the input to the output is entered into the computer, which then uses this data to calculate the spline-fit segments. This method is ideal if the mathematical relationship is knows, for example to calculate the contents of a tank based on the known geometry of the tank.
The ability to apply custom curve linearization opens many possibilities, including the following:
- Altimeters, since the relationship between pressure and altitude is very non-linear.
- Rate of ascent based on successive altimeter readings.
- Square root extraction from differential pressure transducers, whose signal may have zero offset.
- Volume of irregularly-shaped tanks, such as horizontal cylinders, based on measured liquid level or liquid pressure at the base of the tank.
- Non-linear transducers, such as thermistors or CdS cells.
- Fine-calibrating linear transducers, since even nominally linear transducers will have nonlinear components.
- Extending the working range of transducers, since many transducers become nonlinear at the low and high ends.
Measuring tank volume
The Extended Laureate process meter can display the volume of irregularly shaped tanks based on measured tank level or static pressure at the base of the tank. A common example is a cylindrical tank lying on its side. The tank can further be tilted to facilitate drainage, as illustrated. Spherical tanks or spheroidal water tanks are another example.
Rate from successive readings
The Extended process meter 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.
Powering two-wire transmitters
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
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 from -99,999 to +99,999.
The electronics of the Laureate™ digital process and strain meters provide a scalable reading for a wide range of DC input signals from ±200.00 mV to ±660.0 V and ±2.000 mA to ±5.000 A full scale. Common signals include 4-20 mA, 0-5 V and 0-10 V. All ranges are pre-calibrated at the factory, so that recalibration is not needed when changing ranges or signal conditioners.
Isolated Excitation Supply
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. As a result, Laureate process meters are ideal for use in potentiometer follower applications, where the transducer output is a changing resistance. 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.
Fast Read Rate and Signal Filtering
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.
Advanced Meter Features
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.
Options & Other Features
Options include 0-10V and 0-20 mA output scaled to the linearized display, and dual 10 A contact relays or dual solid state relays for alarm and setpoint control. The standard meter can be powered from 85-264 85-264 Vac and 90-370 Vdc. A low voltage power supply for operation from 8-28 Vac and 9-37 Vdc is optional. The display is 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.
||DC Voltage Range
||Error at 25°C ±1 count
DC Voltage & Current
||5 digits, 7-segment, 14.2 mm (.56")
||Concurrent Slope™ (Pat 5,262,780)
||Red or green LED
||60/s at 60 Hz, 50/s at 50 Hz
||-99999 to +99999 or -99990 to +99990 (count by 10 with
||56/s at 60 Hz, 47/s at 50 Hz
||Minus sign, 2 red LED lamps
||3.5/s at 60 Hz, 3/s at 50 Hz
||0.003% of reading/°C
||CMR, DC to 60 Hz
||NMR at 50/60 Hz
||90 dB with min filtering
|Max applied voltage
||660 Vac for 20, 200 and 600 V ranges, 125 Vac for other ranges
||85-264 Vac and 90-370 Vdc
||DC or 49-440 Hz
||25x for 2 mA, 8x for 20 mA, 2.5x for 200 mA, 1x for 5 A
||8-28 Vac and 9-37 Vdc
||Safety-rated to 250 Vac, meter ground to earth ground,
DC to 60 Hz, 4.2 kVp per High Voltage Test
||Connector Pin Assignments
||5 Vdc ±5%, 100 mA max
||10 Vdc ±5%, 120 mA max
||24 Vdc ±5%, 50 mA max
||50 Vdc to meter ground
||0°C to 55°C
||-40°C to 85°C
||NEMA-4X (IP-65) when panel mounted
5672 Bolsa Avenue Huntington Beach, CA 92649 - USA - Ph (714) 622-2000 - Fax (714) 622-2001