Calibration
Calibration Introduction
Calibration Modes
Depending on the measurement mode either Gain or Impedance calibration can be performed.
| Measurement Mode | Calibration Mode |
|---|---|
| S21 | Gain |
| GainPhase | Gain |
| Impedance One Port | Impedance |
| Impedance Adapter | Impedance |
| Impedance External Bridge | Impedance |
| S11 One Port | Impedance |
| S11 External Coupler | Impedance |
| Impedance Voltage Current Gain | Multi Mode (Thru or Open, Short, Load) |
| Impedance Shunt Thru | Multi Mode (Thru or Open, Short, Load) |
| Impedance Series Thru | Multi Mode (Thru or Open, Short, Load) |
Full-Range / User-Range
Full-Range calibration and User-Range calibration differ only in the frequencies that are used to measure the correction factors.
Full-Range calibration measures the correction factors over the "full" frequency range of the Bode device at factory-predefined frequency points.
Calibration values between these frequency points are calculated by linear interpolation.
Advantage of the Full-Range calibration:
Full-Range calibration allows you to change the measurement frequencies without losing thecalibration. Since the correction values are interpolated, they can be interpolated for all frequencieschosen in the measurement.
User-Range calibration measures the correction factors at exactly the same frequency range and frequency points that are used in the measurement currently configured by the user.
Therefore a measurement has to be configured before a User-Range calibration can be performed.
Advantage of the User-Range calibration:
User-Range calibration does not use interpolation. The correction values are measured at exactly the same frequencies as used in the measurement. This results in highest accuracy especially when using long cables or narrow-band probes that show significant gain/phase shift in the measurement range.
Note
User-Range calibration is deleted immediately when the measurement frequencies are changed!
Full-Range calibration and extrapolation below 10 Hz
The Full-Range calibration measures at defined frequencies from 10 Hz up to the maximum measurement frequency of your Bode device. The Full-Range calibration normally starts at 10 Hz to minimize calibration time.
If frequencies below 10 Hz should be included in the Full-Range calibration, you must first configure the lowest measurement frequency before starting the Full-Range calibration. Depending on the lowest frequency in a sweep, Full-Range calibration will start at different frequency values.
| Smallest frequency value in sweep | Full-Range Calibration starts at |
|---|---|
| ≥ 10 Hz | 10 Hz |
| ≥ 1 Hz | 1 Hz |
| ≥ 0.1 Hz | 0.1 Hz |
| 0.01 Hz | 0.01 Hz |
Extrapolation: If the smallest frequency value in the measurement is reduced below the start value of the already performed Full?Range calibration, the lowest frequency point will be extrapolated. Executing the calibration again will perform the Full-Range calibration according to the rules above, starting from 1 Hz.
Note
Starting a Full-Range calibration at 1 Hz, 0.01 Hz and 0.001 Hz significantly increases the calibration duration.