AC Phase Angle Input 4-20 mA Current Transmitter

For angular phase offset in degrees of AC waveforms. DIN Rail mounted, digitally programmable.
  • Isolated 4-20 mA or 0-10V transmitter outputs, selectable.
  • Easy setup using Laurel's PC-based Instrument Setup Software.
  • Frequency from .005 Hz to 10 kHz.
  • 01% accuracy at AC line frequency.
  • Inputs from NPN or PNP proximity switches, contact closures, digital logic, magnetic pickups down to 12 mV, or AC inputs up to 250 Vac.
  • 5V, 10V or 15 V dc excitation output to power sensors.
  • Optional dual solid state relays for alarm or control.
  • Transmits phase angle between two AC waveshapes of similar period.
  • Resolution of 1°, 0.1° or 0.01°
  • Internal conversion of input to six-digit reading:
      - Digital span adjust from 0 to ±999,999.
      - Digital zero adjust from -999,999 to +999,999.
  • Triggers on positive or negative pulse edges.
  • DIN rail mount package only 22.5 mm thick.
  • Detachable screw clamp plug connectors
The 4-20 mA output of Laureate AC phase angle transmitter indicates the lead or lag in degrees from 0º to 360º between two periodic signals having the same period. In the illustration to the left, phase angle is 360*P1/P. The signals are applied to the Channel A and B inputs of the Laureate dual-channel pulse input signal conditioner board.

Phase angle measurement is commonly used with AC power from 50 Hz to 400 Hz. Phase angle needs to be set to zero to synchronize AC generators. It also applies to the triggering of SCRs and Triacs for power control. The phase angle between AC current and voltage determines power factor. The Laureate phase angle meter and transmitter provide exceptionally fast response and high accuracy for low frequencies, such as AC line frequency.

Phase angle measurement with the Laureate phase angle meter or phase angle transmitter requires that two signals with identical periods be applied to Channels A and B. A display from -180º to +180º is obtained by timing the rising edge of one channel and the falling edge of the other channel, and programming a 180º offset. A resolution of 1º, 0.1º or 0.01º is selectable. Accuracy is 0.01% up to 100 Hz, 0.1% at 1 kHz, and 1% at 10 kHz.

Phase angle is determined by timing crystal clock pulses over a specified gate time which is selectable from 10 ms to 199.99 s. By selecting the minimum gate time of 10 ms, the update rate can be up to 20/s for 50/60 Hz AC line frequency. Improved accuracy is obtained by making the gate time long enough so that multiple cycles can be averaged.

Exceptional Accuracy and Stability
The 4-20 mA analog output is generated by an ultra-linear 12-bit (4096 step) digital-to-analog convert (DAC) whose output span can be adjusted from 0 to ±999,999 counts and zero can be adjusted from -999,999 to +999,999 counts. The analog output has a rated accuracy of ±0.05% of output span. The output update rate for a minimum timing interval is 20/sec at AC line frequencies.
Transmitter programming is via the unit's three-terminal serial port using Laurel's PC-based Instrument Setup Software. This software can be downloaded from this website at no charge. The required transmitter-to-PC interface cable is available from Laurel (P/N CBL03).

The transmitters are housed in a DIN rail case that is only 22.5 mm (0.89") thick. Signal connections are via detachable screw clamp plug connectors.


Phase Angle Mode
Item Transmitted Phase angle difference between two waves of same period
Transmitted Units 1°, 0.1°, 0.01°
Frequency Range .005 Hz to 10 kHz
Accuracy .01°, .005 Hz to 100 Hz, .1° at 1 kHz, 1° at 10 kHz
Maximum Timing Interval 200 s
Update Rate
Conversion Interval Gate time + 30 ms + 0-2 signal periods
Gate Time Selectable 10 ms to 199.99 s
Time Before Zero Output Selectable 10 ms to 199.99 s
Transducer Excitation Output (standard)
Jumper Selection 1 10V @ 60 mA, isolated to 50V from signal ground
Jumper Selection 2 5V @ 50 mA, isolated to 50V from signal ground
Jumper Selection 3 15V @ 60 mA, non-isolated
Dual Relay Output (optional)
Relay Type Two solid state relays, SPST, normally open, Form A
Load rating 120 mA at 130 Vac or 170 Vdc, 28 ohms series resistance.
Analog Output (optional)
Output Levels 0-20 mA, 4-20 mA or  0-10 Vdc (selectable)
Compliance, 4-20 mA 10V ( 0-500 ohm load )
Compliance, 0-10V 2 mA ( 5 kOhm load )
Output Resolution 12 bits (4,096 steps)
Output Accuracy ±0.05% of output span
Output Isolation 250V rms working, 2.3 kV rms per 1 minute test
Power Input
Standard power 95-240V AC ±10% or 90-300V DC
Low power option 12-30V AC or 10-48V DC
Frequency DC or 47-63 Hz
Power Isolation 250V rms working, 2.3 kV rms per 1 min test.
Types AC, pulses from NPN, PNP transistors, contact closures, magnetic pickups
Signal ground Common ground for channels A & B
Minimum Signal Nine ranges from (-12 to +12 mV) to (+1.25 to +2.1V).
Maximum Signal 250 Vac
Noise Filter 1 MHz, 30 kHz, 250 Hz (selectable)
Contact Debounce 0, 3, 50 ms (selectable)
Operating Temperature 0°C to 70°C
Storage Temperature -40°C to 85°C
Relative Humidity 95% at 40°C, non-condensing

Typical Applications

Time Interval Mode for Time Delay
For periodic pulses applied to A and B channels, time delays can be measured down to 0.2 µs resolution from the rising or falling edge of A to the rising or falling edge of B (selectable).
Time Interval Mode for Pulse Width
The width of periodic pulses (t1 or t2) can be measured by tying the A and B channels together. As for time delay, readings are averaged over a user-selectable gate time.
Timing Process Dynamics with a Panel Meter and Time Interval Meter
The start and stop pulses used for timing can be generated by the dual relay board in a Laureate panel meter or digital counter. For instance, the start and stop pulse edges can be created as temperature passes two alarm setpoints, or temperature cycles in a hysteresis control mode.
Replacing an Oscilloscope with a Laureate Time Interval Meter
An oscilloscope is great for viewing and timing pulses in a lab. However, in fixed installations where digital timing accuracy and control outputs are required, a low-cost Laureate time interval meter will be the instrument of choice. Resolution to 0.2 µs is feasible.
Using Laureate Meters, Counters and Transmitters to Synchronize Motor Generators
Synchronization of two motor generators requires that the two frequencies be identical, that the lines be in phase, and that the line voltages be close to each other. In this illustration, a single Laureate dual channel counter (or frequency transmitter) measures both frequencies to six-figure accuracy in a few line cycles. Another Laureate dual channel counter (or phase transmitter) measures phase angle to 0.1º resolution. Two Laureate AC RMS Voltmeters, which offer ranges of 200.00 V and 600.0 V, are used to display the two RMS voltage to 0.1% accuracy.
Pinout Laureate 4-20 mA Transmitter, AC Phase Angle Input
(shown with optional dual relay output)
Pinout, Serial ASCII or Modbus Transmitter, Frequency, Rate or Period Input
Transmitter Powering a Single Sensor
Pinout, Serial ASCII or Modbus Transmitter, Frequency, Rate or Period Input Pinout, Serial ASCII or Modbus Transmitter, Frequency, Rate or Period Input
Transmitter Powering Two Sensors Transmitter with Active or Passive Sensors
5672 Bolsa Avenue Huntington Beach, CA 92649 - USA - Ph (714) 622-2000 - Fax (714) 622-2001