Calibration of a Rosemount 3051 HART Pressure Transmitter

This example assumes that the transmitter is isolated from the process and is not electrically connected to a loop power supply. Make basic connections to the 3051 per the diagram in Figure. A separate 250 ohm resistor is not necessary because the 754 incorporates a resistor in series with the loop supply through its mA jacks. The 3051 in this example is configured for psi units.

HART with Pressure Transmitter


  1. Power on the Fluke 754 Calibrator. Press the HART key followed by the Loop Power
    softkey and the 754 will display the basic HART information for the 3051.* Press the HART key again and you are prompted to select the 754 configuration. Selecting
    MEAS mA, SOURCE psi will configure the calibrator to measure the analog mA output and the pressure being applied simultaneously to the transmitter input and the pressure module. (Selecting MEAS PV, SOURCE psi will configure the 754 to evaluate the digital PV output from the transmitter.) Press ENTER to select.* Vent the pressure line and press CLEAR (ZERO) to zero the pressure module. Press the As Found softkey, and then press ENTER to select Instrument for a linear transmitter calibration. (If the 3051 is configured for square root output, select √ Instrument .) Notice that the calibration template is automatically completed with the exception of Tolerance. Fill in the appropriate test tolerance and press Done.

  2. Press the Manual Test softkey to begin calibration. Apply the input pressures ali Accept Point softkey when the correct pressure is applied for each point. When the test is complete, the error summary table is displayed. Test errors exceeding the tolerance are highlighted. When done viewing the table, press the Done >softkey. Press Done again to accept, or ENTER to change the tag, serial number or ID fields.

  3. If the As Found test failed (i.e., there were highlighted errors in the error summary table), adjustment is necessary. Press the Adjust softkey. Select Sensor Trim and press ENTER. (Do not select Pressure Zero Trim It is the same as trimming the lower sensor point at zero, which is useful for pressure transmitters that do not offer Sensor Trim.)

  4. Select Perform user trim–both and press ENTER. Zero the pressure module (vented to atmosphere) by pressing CLEAR (ZERO). Press the Continue softkey and you are prompted for the Lower Trim value. For best results, apply the LRV pressure and press Fetch to load the value being measured by the pressure module. Press Trim Then press Continue to move to the Upper Trim. As before, apply the URV pressure, press Fetch and press Trim If the 3051 is used with the digital PV output, skip to step 8 and perform the As Left test. If the 4-20 mA analog output is used in the process, continue on to step 7.

  5. Select Output Trim and press ENTER. The value of the primary variable (PVAO) is in the upper right corner of the display. This is normally a 4 mA signal. The mA value, as constantly measured by the Fluke 754, is in the center of the display. Press the Fetch softkey to load the measured mA value. Press Send to send the value to the 3051 to trim the output section for the 4 mA value. Press Continue for the 20 mA trim and repeat this step.

  6. After completing Output Trim, press the\ Done softkey and proceed with the As Left verification test. Press the As Left softkey. Press Done and then press Manual Test. Apply the requested pressures and press Accept Point when the readings are stable. On completion an error summary table is displayed. If none of the errors are highlighted, the 3051 passes the calibration test. If errors are highlighted, the test has failed and further adjustment is required. Return to step 5 for adjustment of the 3051.