Calibration and Measurement Tutorial (Opt.004)

After completing this tutorial, you should be familiar with the main operating techniques and features of the N1500A Opt.004 dielectric probe software.

Note: This tutorial uses a 91% isopropyl alcohol and 9% water mixture as the MUT.

  1. Set the frequency range and type of sweep. Click Calibration then Set Frequency. Enter a Start frequency of 500 MHz and a Stop frequency of 2.9 GHz. The default 51 points will cause the calibration and measurement to be done for 51 points linearly spaced between these two frequencies. Click OK. The main window will now show the new start and stop frequencies.

  2. Calibrate the system. The calibration consists of measuring three known standards and using the results to characterize the three major sources of measurement error. The default calibration standards are air, a short circuit, and water.  To ensure measurement accuracy, do not move the probe cable between calibration and measurements. If you have not already done so, stabilize the cable by locking the probe in the mounting bracket of the probe stand as shown in the Set Up Probe Hardware section. Always move the sample to the probe, never move the probe to the sample.

Click Calibration, then Perform Cal. The following prompts appear to instruct you to connect standards.

    1. Leave the probe open in air. This is the open standard. Select OK in the dialog box and a measurement will be made.

    2. Connect the shorting block. The procedure for connecting the short varies with each probe. When the short is connected, click OK.

    1. High Temperature Probe Short

    2. Slim Form Probe Short

    3. Performance Probe Short

  2. Remove the short circuit and place the probe in 25 8507000090003.gifC water.

    1. Measure the temperature of a vial of deionized water with a thermometer. It should be 25 ° C.

    2. Immerse the probe in the water by moving the water to the probe. Make sure no air bubbles are clinging to the probe tip.

    3. Click OK. When the calibration is complete, remove the probe from the water and dry it. You may want to save the calibration by selecting Save Setup under the File menu. You are now ready to make measurements. A measurement can be made by selecting Trigger Measurement under the Measure menu.

  1. Measure the MUT.

    1. Reinsert the probe into the water you used to calibrate the system, then click OK. The analyzer’s display should look like the display below.

8507000000043.gif

    1. Insert the probe into the sample (MUT), then click OK. A measurement will be triggered. The measurement should appear on the display of the computer as shown below. This data can be saved to a file by selecting Save Data under the File menu.

    2. Click Display, then Data to Memory, then Memory 1. A copy of the measured water is made to this memory trace. The Chart and Table will be updated to reflect this change.

    3. Remove the water and dry the probe. Insert the probe into the alcohol and trigger a measurement as before. The display on the instrument will look similar to the one shown below.

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When the measurement is complete, the display on the PC should look the one below.

8507000000048.gif

Note that only the Data trace is changed. The water measurement, stored in Memory 1, remains unchanged.

Click Display, then Traces Displayed to select which of the four valid traces are shown in the Chart and Table.

If you select Data then OK, the displayed window will look like the one below.

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The Chart menu allows you to select which parameter you want to plot. Selecting 8507000090002.gif’’ from the Chart menu plots the measured loss factor.

Autoscale automatically selects the scale for the displayed measurements. When this is selected, the chart changes as shown below.

Alternatively, you can set the scale as desired using the Scale selection.

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Clicking on a point of interest turns on a marker. Notice that the corresponding point in the Table is highlighted.

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The marker can be moved by clicking at another location on the chart or a listed value in the table. The up and down arrows on the PC keyboard also move the marker. The marker can be turned off by clicking on the Marker item of the Display menu.