Following contents will be discussing in this article.
•How a DPC works, basic hands-on.
•Applications & Devices the 744 tests and calibrates.
•Troubleshooting with a DPC.
•Process Loop Overview.
•Hands on training, transmitter calibration, pressure calibration, switch test, source and measure.
•Software; Fluke and partners.
•Press the white “MEAS/SOURCE” key to get the
full MEASURE screen.
•Press gray function keys to select measurement function.
•Depress the VDC button to select Volts DC measurement.
•Use the white “MEAS/SOURCE” key to get the
full SOURCE screen.
•Select a source by pressing gray function keys.
•Split screen, Measure/Source mode for all documented calibrations.
VDC, VAC, Frequency Measurement
Select Function, apply input to measurement terminals indicated
• Volts DC 0-300V Volts AC 0-300Vrms Frequency 0-50Khz With VDC, VAC frequency Measurement you can:
Measure 24 VDC power supplies.
Measure line voltage to powered devices.
Measure voltage on switch contacts.
Measure frequency of rotating devices, sensors.
•Series Circuit measurement.
•Loop Power if selected.
With mA Measurement you can:
Measure 4 to 20 mA signals from transmitters.
Power a transmitter with 24V power supply and measure 4 to 20 mA signals drawn from the 24V power supply.
Resistance & RTD Measurements
• 8 types, Pt100..1000,Cu,Ni
• Hook up per displayed hook up Diagram With RTD and ohms measurement you can:
Measure point to point continuity with beeper.
Measure and verify process temperature using an RTD probe (like a thermometer).
Verify 250 ohm shunts in process I/O.
•TC types ENJLKTUBRSC.
•Reference temperature and measured mV on display With TC Measurement you can:
Measure and verify process temperature using a TC probe just like a thermometer.
VDC, Frequency Source
Output taken from these Source terminals:
Volts DC 0-15V, Freq. 0-50Khz
–Sine wave or square wave
–P-P amplitude, selectable to 10V
With VDC, Frequency Source you can:
–Test 1-5, 0-10V process I/O.
–Test turbine meter and PLC frequency inputs.
mA Sourcing & Simulation
–24V burden max.
–Draw requested current from external voltage source up to 30 VDC
– With mA source/simulate you can:
–Source mA input signals into I/Ps, PLC or DCS 4 to 20 mA I/O, valves
–Simulate and perform a substitution test for transmitters
•TC types ENJLKTUBRSC
•Read reference temperature and output mV on display.
With TC source/simulate you can:
–Simulate temperature into transmitters.
–Verify mA output.
–Simulate TC temperature into indicators.
–Compare indication to sourced value.
–Simulate temperature into switches.
–Verify contact state change as temperature crosses set point.
Resistance & RTD Sourcing
•RTD Source from these terminals
•8 types, Pt100..1000,Cu,Ni
With RTD source/simulate you can:
–Simulate temperature into transmitters, and verify for correct mA output
–Simulate RTDs temperature into indicators, compare indication to sourced value
–Simulate temperature into switches verify contact state as temperature crosses set point
Applications for a DPC •Measure transmitter outputs, valves, test process I/O
–Measure or source/simulate 4-20mA signals, voltage.
•Measure process temperatures or test devices with TC or RTD inputs
–Measure or simulate (source) eleven types of TCs, 8 types of RTDS.
•Measure the pressure applied to a transmitter, switch or output of an I/P
–Measure absolute, gage or differential pressure.
Test the input of tachometers, turbine meters (flow), output of flow sensors
–Measure or source frequency.
•Test temperature and pressure switches, monitor contact closures •Perform remote tests, ramp the source with a linear or step ramp •Power a transmitter, supplyloop power •Simulate transmitter inputs while simultaneously measuring their output for a calibration test (dual screen/channel source/measure)
Process Devices To Test •Transmitters
–Pressure and Temperature
–Solid state or dry contact switches that change state with a change in pressure or temperature
• I to P, current to pressure converters
–4 mA to 20 mA input, 3 psi to 15 psi or other pressure range output
–Pressure or mA input controls open/close of valve
–Analog or digital, local indicators
•Process I/O (Input/Output)
–Analog inputs and outputs of DCS or PLC systems
– MIN-MAX Recording
•The “MIN MAX” soft key controls the saving of the minimum and maximum values of a series of measurements
•From the MEASURE screen, depress more choices and Min/Max
•Depress More Choices, and Save to enter into memory
•Depress Continue to enter a Tag for the measurement.
– Data Logging
•Log up to 8000 measurements
•Measurement rates from 1/minute to 1/second
•Data available via a PC using DPC/TRACK
– Step Function
The Step Function can be accessed from the Source or the Measure/Source Mode.
Two Step Function modes Manual Step
–Set Step size
–Change the source with Up and Down arrows
–Per setup screen
•User-programmable test source
•Troubleshoot remote installations
•Verify indicators, displays and positioners
– Ramp w/Trip Detect
•Works with any sourced function
•SOURCE Volts dc…More choices…Ramp
•4 to 5 V 20 sec Enable Continuity
Capture the applied value where a process switch changes state