Laurel

Laureate™ Frequency, Rate & Period Meters

(With dual, independently field-scalable channels)
Features
Standard Counter
  • Two independently field-scalable channels selected by front panel pushbutton.
  • Inputs from NPN or PNP proximity switches, contact closures, digital logic, magnetic pickups down to 12 mV, or AC inputs up to 250 Vac.
  • Line frequency measurement to 60.0000 in a few line cycles.
  • Square root extraction.
  • Green or red LED display.
  • Optional dual relays, 4-20 mA & 0-10 V analog output, RS-232/485 I/O, parallel BCD output, low voltage AC or DC power.
  • Frequency from 0.005 Hz to 1 MHz.
  • 6-digit resolution at update rates up to 25/s.
  • Selectable "count by" of 10 or 100 with rounding.
  • Isolated 5, 10 or 24 Vdc excitation supply to power sensors.
  • NEMA-4X (IP-65) front panel, 1/8 DIN case.
  • Certified to UL 3101-1, CAN/CSA-C22.2, EN 61010-1 (CE Mark)
Extended Counter All capabilities of the Standard Counter, plus:
  • Rate and total simultaneously.
  • Arithmetic functions A+B, A-B, A*B, A/B, A/B-1 (draw).
  • Linearization of non-linear inputs.
  • -----------
Description
The Laureate dual-channel frequency, rate and period meter is a basic operating mode of the Laureate counter with the FR signal conditioner board. It can display frequency from 0 Hz to 1 MHz, rate in engineering units, and period (inverse of frequency). The normal displayed value can range up to 999,999 counts. Above that level, the display will flash and go into four-digit XXXXEX scientific notation. Square root extraction is standard. Each channel (A or B) may be independently scaled for frequency, rate or period. The displayed channel is selected via a front panel pushbutton.

Examples of applications are the accurate display of AC line frequency, RPM, speed from proximity switch inputs, and flow from turbine flowmeter inputs.

Fast, High Resolution Measurement
The Laureate counter determines frequency by timing an integral number of periods over a specified gate time, and then taking the inverse of period. Rate is obtained by multiplying the input by a scale factor. The inverse period approach allows greater accuracy and faster update times than conventional meters which count signal pulses over a specified time interval. AC line frequency may be accurately measured to 50.0000 or 60.0000 in a few line cycles. 1000 Hz signals may be measured to 0.01 Hz resolution at up to 25 per second. Fast response is ideal for alarm and control applications.

To reduce the effects of signal noise, a count by 10 or 100 feature with rounding is selectable. Variations in the displayed reading can also be reduced by selecting a longer gate time. An adaptive filter can reduce variations due to noise while rapidly responding to actual changes in the signal.

Extended Counter Capabilities
An Extended counter version provides capabilities beyond those of the standard counter:

Rate and total simultaneously. One channel can display total while the other displays rate. The selection for either channel is via a front panel pushbutton. This mode is ideal for flow applications when the same signal is applied to both channels.

Linearization of nonlinear inputs. Exceptionally accurate custom curve linearization capability allows linearization of the low end of turbine flowmeters. For setup, up to 240 data points can be input into a spreadsheet or text file by the user. The computer then calculates nonlinear segments, which are downloaded into the meter via RS-232. The Extended version allows linearized rates to be totalized.

Arithmetic functions. The Extended counter makes arithmetic functions available, namely A+B, A-B, A*B, A/B and A/B-1 (draw). For example, A+B allows two input flows to be summed for total flow, while A-B allows outflow to be subtracted from inflow for net flow. If transducers with a frequency output are used, A*B allows horsepower to be displayed based measured torque and RPM, or based on force and velocity. A/B can be used for the proper mixing of ingredients, while A/B-1 (draw) is used to compare rates for stretching or tensioning.

Universal Signal Conditioner
The dual-channel signal conditioner accepts inputs from proximity switches with PNP or NPN output, TTL or CMOS logic, magnetic pickups, contact closures, low-level outputs from turbine flow meters down to 12 mV, and high-level AC line inputs up to 250 Vac. Nine hysteresis and input levels are jumper selectable for reliable counting. A 1600 Hz low-pass rolloff filter and debounce times of 3 ms or 50 ms are also selectable. A built-in isolated 5, 10, or 24 Vdc excitation supply can power proximity switches and other sensors, and eliminate the need for an external power supply.
Other Features and Options
Plug-in isolated analog output, dual setpoint controller, and RS232/485 serial data I/O or BCD output boards can upgrade the Laureate from a stand-alone monitor to system interface and control. Laureate meters and counters meet NEMA 4X (IP-65) standards from the front for high pressure washdown when panel mounted.

Specifications

Display Excitation Output
Readout 6 digits, 7-segment, 14.2 mm (.56") 5 Vdc 5 Vdc ±5%, 100 mA max
Color Red or green LED 10 Vdc 10 Vdc ±5%, 120 mA max
Range -99999 to +99999 XXXXEX scientific notation beyond 999999 24 Vdc 24 Vdc ±5%, 50 mA max
Indicators  4 red LED lamps Output isolation 50 Vdc to meter ground
Accuracy Electrical Connections
Time Base Crystal calibrated to ±2 ppm asd
Span Tempco ±1 ppm/°C (typ)
Long-term Drift ±5 ppm/year
Conversion Power
Frequency Technique Inverse period Voltage, std.
85-264 Vac and 90-370 Vdc
Conversion Time Gate time + 30 ms+ 0-2 signal periods Frequency
DC or 49-440 Hz
Gate Time Selectable 10 ms to 199.99 s Voltage, opt. 8-28 Vac and 9-37 Vdc
Timeout
Selectable 10 ms to 199.99 s
Power isolation Safety-rated to 250 Vac, meter ground to earth ground,
DC to 60 Hz, 4.2 kVp per High Voltage Test
Output & Display Updates Same as conversion time ------ ------
Inputs
Types
AC, pulses from NPN, PNP transistors, contact closures, magnetic pickups Selectable Hysteresis (-12 mV to +12 mV), (+30 mV to +60 mV),
(-30 mV to -20 mV), (-150 mV to +150 mV),
(+350 mV to +600 mV), (-600 mV to -350 mV),
(-1.15 V to +1.15 V), (+1.25 V to +2.1 V),
Grounding
Common ground for channels A & B
Channel A Frequency 0.005 Hz to 1 MHz Rolloff Filter (-2.1 V to -1.25 V)
Channel B Frequency 0.005 Hz to 250 kHz Debounce Time Selectable, none or 1600 Hz
Selectable 0, 3, 50 ms
Environmental
Operating Temperature 0°C to 55°C
Storage Temperature -40°C to 85°C
Relative Humidity  95% at 40°C, non-condensing
Protection NEMA-4X (IP-65) when panel mounted

Typical Applications

DC-panel-meters
AC Line Frequency
The Laureate will accept line voltages up to 250 Vac and display line frequency to 6-digit accuracy (50.0000 or 60.0000) in a few line cycles. Fast low frequency response is achieved by timing the period and taking its inverse
DC-panel-meters
RPM and Speed
The Laureate can sense the low-level signals from magnetic pickups or the NPN or PNP transistor output of active sensors. These can be powered directly by the meter. Display in RPM or units of speed is achieved by mathematically scaling the meter.
DC-panel-meters
Flow Rate and Simultaneous Total
The Laureate is compatible with all flowmeters which generate pulses at a frequency proportional to flow rate. The Extended version can display scaled rate or total for the same input at the push of a button, and alarm from both the rate and total. The Extended version can also linearize flow transducers so as to extend their dynamic range.
DC-panel-meters
Combining Two Rates
The Extended Laureate offers A+B, A-B and A/B arithmetic functions. A+B allows two input flows to be summed for total flow, while A-B allows outflow to be subtracted from inflow for net flow. Flow ratios aid in the proper mixing of ingredients
DC-panel-meters
Linearizing Nonlinear Inputs
The Extended Laureate can linearize pulse output flow meters, which tend to be nonlinear on the low end. In particular, linearizing improves the dynamic range and accuracy of turbine flow meters.
DC-panel-meters
System-level Capabilities
The Laureate dual channel rate meter can independently scale, display and alarm two pulse input channels. All signal or alarm data can further be transmitted via RS-232 or RS-485, including peak readings and arithmetic combinations of the two rates. The displayed rates can also be transmitted as isolated parallel BCD and isolated 4-20 mA analog output.
Purchase
5672 Bolsa Avenue Huntington Beach, CA 92649 - USA - Ph (714) 622-2000 - Fax (714) 622-2001